Yes, in a large range around you. XP scaling due to Intelligence is also shared intrinsically, so it doesn't matter if the Wizard with high Int. picks up the XP or the 'me kill bad guy with sword' Knight does.

Have you bound your G and H keys properly? Check by going to controls and finding the 'RPG Second Action' and 'RPG Third Action' bindings.

Yes.

Kind of? There seem to be some issues like no energy regen, and I'm not sure why.

That's not a question.

Much better, but probably not. Before blaming my mod, please check to see if other big mods have updated, if you've subbed to any other mods recently, if you accidentally have two copies of my mod (yes, this has happened), and please post a link to a pastebin with your starbound.log.

Maybe? It depends on how you asked and what you asked for. Some things are just not possible, some take a long time, some require massive UI overhauls, some would break compatibility with other mods, and sometimes I just don't think it's a good suggestion.

I like having variations between players due to their in-game choices (gender, race, class, etc.), and if it wasn't as difficult to make Specs, I would make Race-specific ones too. I also like having in-universe reasons (lore, essentially) for why certain things are locked.

You probably have Classic Mode enabled. Classic Mode makes the game behave like a classic RPG, which means certain classes can only use certain weapons.

Meteoric Metal: Masteroid.
Spiral Energy: Ringram, Monopus, Hypnare, Mandraflora.
Parasitic Goo: Oculob, Miasmop, Sporgus, Paratail, Parasprite.
Dying Star: Narfin, Petricub, Lumoth, Wisper.
Ether: Squeem, Skimbus, Spookit, Gosmet.
Gun Parts: Most Space Robots, Bandits.
If you don't know what these enemies are, look them up using the Starbound wiki.

Anvil for Class Weapon, Furnace for Class Item. Specialization Weapons can only be crafted in Tier 3 Anvils.

Use the proper element to defeat shielded enemies. Look through the Lore Tab for more information.

Yes. Class Reset Scrolls can be found by defeating high tier monsters (at a low chance), and can be crafted via the Mastery Shop at level 50 (or on Prestiged Characters). You can also use the reset button on the Overview Tab, but this is a hard reset, rather than just a Class reset, so only use it if you don't care about losing all progress.

You go back to Level 1, lose your Affinity (and Affinity Upgrade, so you'll have to find another Upgrade Scroll), lose your current Class and Profession, and your stats will be reset. However, Mastery and Challenges are kept unlocked, your currently unlocked Class Techs will be kept, and any stats gained via Stat Scrolls should be refunded as well.

Nope. It will work on any new or old characters you have.

Yes, but I recommend the following:

• Before subscribing, make a backup of your character.
  
• Before un-subscribing, use the Reset button in the Mysterious Book
  
• Before un-subscribing, remove all items related to this mod from your world.