First lets get the auto lose options out of the way (you automatically lose the game if you pick this option):

don't sign the treaty

refuse to get gangbanged

drink the wine the regent wants you to drink

either the 'money is power' or the 'money is time' password options

rejecting the information broker's offer to sleep with you for information

refuse to pay any of the payments to Cestern

refuse to be a sex slave when attempting to get the alliance Leon suggests

surrendering to Cestern

putting your army in the mountains or plains

not luring the enemy into a trap in the final battle (it says allure and not lure)

failing to secure support of the people at night when trying to defeat the rebellion (it won't fail immediately, but you don't have time to actually get everyone so you lose the game when the rebellion kicks off) there is also a score check in which you need 20p (it tells you this in the game)

At certain points in the game you need a certain minimum score or else you lose:

at about month/day 10 you need at least 40 military and 20 agriculture

at the end of the first and second year you need 20 economy

around month/day 21 you need 20 or more politics

towards the mid to end of year 3 you need 50 or more in economy

when choosing to defend or retreat you need the needed points for the option you choose or you will auto lose

after getting the option to retreat you will get the option to attack or defend, you will need at least 60 agriculture at this point


at certain points you will need a certain minimum score to pick different options:

at the end of the first and second year you can choose to lose, so technically this falls into these as well above

if you decide to use money instead of sleeping with the information broker you will need at least 10 economy or you can't choose the option after deciding to spend money (you will end up losing the game due to failing to gain his support)

when asking the nobles for money you need at least 30 politics to get your politics value as income for your economy (if you have 45 politics you get 45 economy points), otherwise it is a smaller amount

after the war has kicked off you will get an option to buy food, you need at least 20 for the massive buy option, 15 for the moderate buy, and 10 for the small buy, if you can't afford these you will do the second massive buy option which is actually not buying anything (it is a typo), as you will need 60 agriculture to win the war and at this point the maximum gains for agriculture is 20, while the maximum losses can be 13 make sure you have enough food (agriculture points) and buy accordingly

you will need at least 6 economy to build copy cestern's defense at the border otherwise you don't get the 10 military points

updating your equipment after the war as started requires at least 10 economy otherwise you don't get the 15 military points

when asked if you want to 'mobilize' the army you will need at least 30 population score in order to get your population score plus an additional 2 as military score, if it is below 30 then you get a smaller amount just like asking the nobles for money above

when you hire mercenaries you need at least 20 economic points for the big money option, 15 for the moderate money option, and 10 for the small money option similar to the buying of food above, though this time there is no typo so the don't spend anything option says no money

when asked if you want to defend or retreat you will need at least 130 military points to defend successfully, and 40 to retreat successfully, otherwise you will lose the game if you lack the points for the option you choose

when asked if you want to buy the better crossbows you will need at least 30 economy points for that option, otherwise you do not get the 60 military points

I have gone negative in politics and popularity testing out the options with no ill effects, so the amount of points don't really seem to matter as long as you make the needed checks. It would make sense for their to be a minimum military score to defeat the enemy even when picking the retreat option, but I have never had a low enough military score it would seem at that point to get a different outcome. Though to be fair I always had above 130 military points by that time even if I didn't focus on it. I also have not had my economy go negative during the battle, so I am not sure if that matters at all either.

Sigrid
They aren't actually endings, but their back stories. To get Sigrid's you need to send her off to get gangbanged in your place as well as heading her warnings that Hall will want her to pay the price if she goes with him. After you have done both of those when you are given the option of picking between Leon and Sigrid to comfort you about the war you pick Sigrid. She will come and comfort you and you will get her backstory at that point.

Leon
For Leon all you have to do is sleep with him as a reward instead of saying you will give him enough money so that he will be wealthy his entire life (that option doesn't cost anything either strangely enough). When you get the option to have him or Sigrid comfort you pick him and he will comfort you and you will get his backstory.

Key: M=military F=agriculture N=politics P=popularity E=economy

Key: M=military F=agriculture N=politics P=popularity E=economy

Key: M=military F=agriculture N=politics P=popularity E=economy

Key: M=military F=agriculture N=politics P=popularity E=economy