My suggestions will be ranked in this order:
S - Best of the best.
A - Very powerful, but not as powerful or comes with a drawback.
B - Powerful, but significantly below an A.
C - Not for speedrunning, but still useful in higher difficulty settings.
D - Insignificant, but not harmful
E - Significantly underpowered compared to alternatives.
F - Actively detrimental.
I will be listing them by order of my recommendations.
Different values will be listed for each rarity that I am aware of.

For the 0.5.5 patch, the damage over time effects of Poison and Burn are very small (between 10 and 30 damage from my experience), thus I consider them straight up bad investments in comparison to taking Shock or crit.
Freeze application does not seem consistent and I cannot tell what the constraints are, and crit seems more powerful than flat damage, so I value Ice/Water Normal Attack/Hustle Techs less than Shock or crit but more than Poison/Burn.
I also find knockback to be an active detriment in most situations, duo to it causing most followup attacks to miss. This can double the length of a run if you have too much.

The second note for 0.5.5 patch, I consider the lightning Elemental Force to be the most useful one as a: the lightning bolts + shock effects scale better than all of the others b: applying shocked has great synergy with other lightning effects c: the bolts automatically and precisely hit enemies without you having to aim them.
The second best is water, which has both synergy with other effects and keeps you from dying!
On the other hand, I consider wind to be the one detrimental Force to get. The tornado has a strong knockback. It's not a run-ender, but I'd avoid it if possible.
I'd definitely recommend abandoning and starting a new run if the first element you get isn't either lightning or water.
(You acquire an Elemental Force effect by having 2 Ratakaruta of one element, with a cap of 3 out of 6 elements.)

My third and final note is that, because of the above logic, I will be assuming you ideally have some form of consistent Shock in your run by the time you reach the third stage (if RNG is willing of course), and that you will fill in the remaining gaps with crit (wind). Runs vary of course, so it's up to you to grab enough Shock to get by each run and not use this guide as the be-all and end-all.
At days end, my priority is Lightning until enough Shock > Wind but ideally no Force > Water > Ice if you have some form of Freeze application > Fire if you have Burn application or Poison if you have application.

Sacrificial Valor
Sacrifice some HP to temporarily increase the attack power of Hustle Techs by 20%.
This is a very vague description and I'm honestly not sure how this functions. I don't know what it means by "temporarily," which means I don't know how frequently you benefit from it. It appears to drain about 10 HP upon Hustle Tech use, and it won't drain again for about 20-30 seconds. If it's 10 HP per 20-30 seconds for a 20% damage increase, I'd put this at B tier purely due to how it conflicts with Chilly Challenge (damage increase above 75%), but if you have plenty of health/take no additional damage due to shields then I could see it being an A tier.


Big Booms
Periodically creates explosions around Ratatan, dealing damage 20%/30% of Ratatan's max HP.
Very small radius. Once every 4-6 seconds.

Spicy Guts
Increases attack power by 25%/50%/100% based on how much Ratatan's health has decreased.
Don't know how much is "how much."

Spicy Guard
Reduces damage received by 10%/20% while Ratatan HP is at 50% or less.

Collector's Cover
Each item you acquire reduces damage taken by 1% (max 10%).


Burning Bummer
Enemy attack power decreases by 20%/40% while inflicted with Burn.

Blaze Ball
Fire Elemental Force damage increased by 50%.

Burning Boost
Recovers 3% HP every 2 secs near Burning enemies when below 30% HP.


Burning Blast
Normal Attacks create and explosion that deals an additional 15%/35%/45% damage and inflicts Burn.

Hustle Blast
Hustle Techs create and explosion that deals an additional 15%/25%/45% damage and inflicts Burn.

Burning Dread
Burning causes Teshita to flee for 2/3 seconds.
By "flee" they mean run back and forth. Less annoying than knockback and stops them from attacking, but can still cause you to miss.

Barrier Swell
MP recovers by 2% per second while protected by a barrier.


Splash Initiative
Increases attack power by 10%/30% for 30 second at the start of battle.

Splash Barrier
Gain a barrier (HP 20%) at the start of battle.


Whirlpool Shield
Increases max barrier strength by 50%.
Great for survivability in harder difficulties, overkill for normal farming runs.

Splash Barrier+
Increases barrier strength by 10%/20%/50% when acquired.

Oasis Power
Attack power increases by 5%/7% when using healing springs.
Not retroactive.


Raindrop Hop
Jumping drops a water orb, dealing 20 damage + 150% of barrier to nearby foes.
This aoe effect is very narrow and has no verticality, meaning it cannot hit half of the bosses in the game and is difficult to hit more than one enemy with it, not to mention it is quite dangerous to use. However, it can deal a hefty amount of damage (upwards of a flat 500) and can be used 3 times before your next rhythm command, so it's not useless.


Splash Combo
Defeating enemies with a water splash creates an additional water splash that deals +20%/+25%/+30% damage.
Unsure if this works with Raindrop Hop.

Supreme Soaker
Increases water splash damage by 60%/120% and inflicts knockback.
The damage increase is likely worth the knockback, but I'm assuming you don't have splash here.


Soaking Splash
Creates a splash of water when landing Normal Attacks, dealing an additional 25%/55%/70% damage.

Hustle Splash
Creates a splash of water when landing Hustle Techs, dealing an additional 25%/40%/55%/70% damage.

Chilly Challenge
Increases strength by 25%/35%/50% while Ratatan HP is at 75% or higher.


Glacial Heal
Increases HP recovery. Recovers 10%/30%/60% of max HP when acquired.

Grand Finale
Fully recovers if HP is at 75%/60%/50% or above at the end of battle.
I believe this is only for Ratatan, not Cobun. Not sure.

Grand Entrance
Recovers 2% HP every 2 secs for first 30 secs of battle.

Macho Minuet
Max HP increases by 10/15 for each boss enemy defeated.
Not retroactive. Counts mini-bosses.


Shatter Smash
Attacking Frozen enemies when their HP is low enough shatters the ice and deals extra 500%/1000% damage.
Unsure how much is "low enough."

Frigid Fury
Frozen enemies take +75%/+100% damage.

Slow Thaw
Teshita and native fauna suffer -40% movement speed when Freeze ends.


Bitter Chill
Increases Normal Attack damage by 20%/25%/35%/45% and has a chance to inflict Freeze.

Hustle Chill
Increases Hustle Tech damage by 20%/25%/35%/45% and has a chance to inflict Freeze.

Goodie Gatherer
Increases the amount of items acquired by 1.
No ranking since this gives no combat benefits.


Boss Basher
Deal +10%/+15%/+25% damage to boss enemies.
Unsure if this includes miniboss-type enemies.


Poison Pinch
Poison damage triggers 20%/50% faster.

Poison Drop
Increases Poison Elemental Force damage by 50%.

Toxic Curse
Teshita and native fauna suffer -40%/-50%/-60%/-80% movement speed while Poisoned.

Toxic Corruption
Poisoned enemies suffer -10%/-30% defense.

Toxic Boost
20% chance to deal +100% damage to Poisoned enemies.


Poison Punch
Normal Attacks inflict Poison on enemies.

Toxic Hustle
Hustle Techs inflict Poison on enemies.

Autocharge+
MP recovers by 10 every 4/3/1.5 seconds while nearby enemies are Shocked.
Dangerous to use against large groups as you have to stand nearly right on top of a Shocked enemy for it to work, but this is the effect that lets you non-stop spam Hustle on bosses.


Zap Strike
Normal Attacks inflict Shock on enemies.
Only A instead of S because you can apply Shock in other ways, and crit/Wind might be better.

Hustle Zap
Hustle Techs inflict Shock on enemies.
Only A instead of S because you can apply Shock in other ways, and crit/Wind might be better.

Thunder Freebie
15%/33%/50% chance of reducing Skill or Hustle Tech MP cost to 0.
Only A instead of S because of relying on chance.


Thunder Recovery
Recover 1%/2%/3% MP when defeating enemies with Hustle Techs.

Amped-Up Zapper
Using Hustle Techs increases Normal Attack damage by 20%/30%/50%/75% for 6 seconds.
More useful the less MP restoration you have.

Zap Zinger
Shock damage increases by 25%/50% and briefly downs enemies.

Wizardly Waltz
Max MP increases by 3%/5% for each boss enemy defeated.
Not retroactive. Counts mini-bosses.

Bolt Boomer
Hustle Techs have a +50%/+100% chance to trigger additional lightning bolts.

Whirlwind Strike
Normal Attacks have a +40%/+60% chance of landing critical hits.
Only A instead of S because you may need a source of Shock/Lightning instead.

Hustle Strike
Hustle Techs have a +40% chance of landing critical hits.
Only A instead of S because you may need a source of Shock/Lightning instead.

Hurricane Combo
Critical hits inflict +60% damage and knockback.
The insane damage increase is worth the unfortunate knockback.


Hurricane Haymaker
Critical hits deal a massive +50%/+150% damage if enemies' HP is below a certain level.
Unsure what "a certain level" is.

Knockback Crusher
Knocked back enemies take +10%/+15% critical damage for a short time.
Unsure if works on bosses/enemies that can't be knocked back.

Hurricane Havoc
Cobun stop moving when attacking but gain 50% more critical damage.
The damage increase is incredible, but Cobun no longer walking towards enemies before doing their attack animation can be a real pain depending on your weapon choices. Fortunately Hustle Techs often provide long-ranged attacks or leaps towards the enemy.


Cha-Ching Critical
Gain +5/+7 tokens when defeating enemies with critical hits.


Lucky Rebate
10%/20%/50% chance for partial cashback when purchasing items from the Shop.
Unsure how much "partial" is.


Whirlwind Tornado
2 traveling tornadoes appear when using Wind Elemental Force.
Even more tonadoes? No thank you! The only logic to it that I can think of is that it'll quickly push enemies to a back corner where they can only be bounced slightly in the air. This effect will most likely add 10 minutes to your run, though.