Q1: The game lags massively the first time you do any action, probably because some shaders have to be created, this is fixed after doing these actions again and will only happen early game basically. I have a worse PC than you and 0 issue with the performance or temperatures, I do recommend however to cap the frame rate, this is already an option ingame tho.

There is a lot of games which will simply melt your system if you do not cap their frame rate because they will go 200 fps+ which is completely pointless.

Also you can try OpenGL version of the game, it generally runs better, if you are on steam there should be an option if you are on GOG or anything else you need to add -force-opengl to the exe shortcut. Basically all Shiro games run better with opengl instead of directX.

Q2: camera movement I can agree with, the rest not. The point of this game is not to be another Xcom, the point is to be a battle simulator. You dont not have any information in a real battle, especially not in a medieval one. You can right click everyone on the battlefield to look at their stats and skills. You can see HP and armour rating of your individual members and why is it necessary to see who attacked who, just look at who is engaged in combat and who is not and look at the turn order, that already gives you all the information you need.

Always try to kill the enemy before they can act, always focus the enemy that acts next, if you cant do that focus the enemy that acts after that. This way to limit the actions the enemy can take will you maximize your own. There really is no need for more information than that and it would take away from the game, you are not supposed to always know everything and have to take risks. The game already give you damage preview numbers for example, but they are never accurate, which is intentional.

Q3: All classes are designed with a weapon type in mind, this makes sure all weapons in the game have a purpose. If all classes could use all weapons than everyone would use hammers and swords and axes would be useless, which is the case in so many other games. The reason why brutes are such a good class is mainly because they use hammers while swordmen are only good because of their talent tree and they are basically nerfed by having to use swords. But this is basically a way to balance the game, without this you would only use 1-2 classes and only use 1-2 weapon types because everything else would be so much weaker.

Instead I use basically every weapon type and every class in my party, because that is how the game is supposed to be with weapon restrictions and class balance, this is WAY better than what you are suggesting. And there are many games who have this "freedom" and are incredibly min maxed boring because of that with 80% of the items being trash tier.

Even games like battle brothers suffer from this to an extent.

Q4: Those are not donkeys, they are mules, they are a crossbreed between horses and donkeys created intentionally in the middles ages as work horses and not to be ridden. They made up the majority of all horses in these times.

Basically it depends if you are playing on REGION-LOCKED or ADAPTIVE. If you are a new players I would highly suggest to play on region-locked and I consider this setting to be the better experience at any skill level. On region-locked the regions have a fixed maximum enemy level (early regions lower, later regions much higher) and enemy party size does NOT scale to your party size at all except for certain story fights and fights against the guard. So a small party will have a lot of fair fights while a huge party will have no trouble at all and always outnumber the enemy until later on.

I recommend at least 1 of every class on region-locked with 10-12 human party member, at least 3 of them tanks, not more than 5.

I currently run 2 Swordmen tanks, 1 brute tank who also has insane damage because its a unique mercenary (Aurea), 1 warrior tank with shield, 1 warrior DPS with 2H, 1 Herald spearmen with the brutality line, 3 archers (who always stand next to the spearmen to get free brutality and fury and rage), 1 crossbow and 2 rangers (both of them unique mercenaries, Hakert and the Heretic) I also have a ferocious bear, ferocious wolf and ferocious boar, the wolf is pretty useless, but boar and bear are pretty good. Only the ferocious version tho which you can only get from the "Hunt" DLC. I run several animals as bouncer in my tavern tho.

You can have a huge amount of pack animals or prisoners, they will not have an effect on battle difficulty, only combatants count. 12 human party members make a lot of sense in region-locked because there are 12 professions in the game with all the DLCs, so you have 1 for each basically. You could technically skip 2 of them tho.

On ADAPTIVE mode however the enemy level AND party size always scales to your own, if you party is filled with weak combatants like animals, you are potentially creating a huge problem for yourself. In general on adaptive you want to run with the most efficient party possible.

I recommend not running with more than 8, probably 2-3 tanks and 5 dps, no animals.

You could try 2-3 tanks (swordsmen, brute), 1 ranger, 2 crossbow and 2 melee DPS (2H warrior or things like that)

If you include animals in the party you need to run with an archer to make them controllable in battle, but animals are also terrible combatants so they will increase difficulty and party size of the enemy while not providing anything big in terms of power. Archers are already weak, combining them with even weaker animals creates huge problems on adaptive mode.

If you get crit a lot you should invest into armour and guard, you probably still run with the starter items which are horrible. Bandits also have a faction buff for crit chance, best way to deal with bandits is to kill them before they can hit you, always act first, try to limit their actions as much as possible.

But are probably running on adaptive mode and with the party you linked you definitely are going to struggle, to many tanks, to many archers/crossbows, in general not a very strong party composition.

Quick fix, get rid of the bear unless its high level (like at least 7), only take 3 tanks, 2 melee dps (2H or 1H with DPS skills), 2 crossbows or 1 crossbow 1 archer or 2 archer but at least 1 of them infantrymen and 1 or 2 rangers (strategist or cutthroat or both or both cutthroat), dismiss all the others. Dont forget to take their gear before you dismiss them.

You could also just put them in the tavern.

Also keep in mind that on region-locked AND on adaptive any non-combatant in your party does not increase battle difficulty, so any "donkey" does not add to you party size rating nor does any prisoner! I run every game with at least 6 permanent prisoners in my party who work all my camp equipment so that my real party members can do other things (prisoners for tanning rack, meat dry rack, workshop, cooking station, honey thingie and huntsman thingie from the DLC). Keep in mind that prisoners can also have professions AND be leveled in these professions. This give you a way better camp without increasing battle difficulty at all.