I'm seeing that you are genuinely frustrated and not trolling. So I will explain it.
Then why dont they even give us a propper way of loading custom assets?
You have Modding Tools for that - it's the proper way of loading custom assets. And again, it's a huge step-up compared to Warband. Because in Warband, there were no official tools. Without mtarini's OpenBRF, we wouldn't have this many M&B mods. And community had to wait fairly a long time for that. So you can understand how great it is to have official tools for asset integration.
Even Total War didn't provide Official Modding tools for a long time - so it's not very logical to expect this from a mid-sized company this fast.
Like if i want to add new sprites i have to actually add some C# code,
You can add new Sprites via Spritesheet generator as far as I know and this doesn't need any C# code at all - only XML tweaking if you want to see it in game. I haven't added anything so I'm not entirely sure but I'm 95% certain that it doesn't require C# code. It does require a module though.
if they really want to support modding, why didnt they make any folders where we can just put our assets and they get loaded?
Perhaps they will do that in the future? You are forgetting the fact that they are not making a game engine - they are making a game. And usually, you do the game first, and then make it accessible/moddable later on. And as you can see, the game is not ready yet.
Another questionable choice when it comes to making a game moddable, why didnt they keep any API documentation from the start? It would be alot easier for them, than having others reverse-engineer their whole game...
No it wouldn't. Apart from several Engine Interface Calls, the rest doesn't require to have API documentation. Because:
- Most of the code used by modders are not "simple" methods created by TW. So knowing there is a method in TroopRoster that returns List<TroopRoster> won't increase your modding skills significantly. Which, again, this information can be seen by a click of a button anyway. And in matter of fact, TW has a very low amount of public and helper methods in the game right now. Even if they make them public, you would still require to see the exact code to manipulate that. Especially if you want to change something in the function, you have to patch it. And to do that, you need to know exact code of that function.
- Its pointless to have it while you change the structures and methods overnight with different updates. If you had API documentation,, you also had to update that over and over countless of times in EA. They can make it after EA - once everything stabilized and when they finalized their architecture.
Even if modding is their least concern, they could at least have given us an ACTUAL sandbox mode like in other games, where you just start on an empty map and can add the assets you like without fighting all the native stuff that gets in your way.
You completely misunderstood the Sandbox Mode in that announcement. Sandbox Mode doesn't mean Code Sandbox Mode. What they mean as Sandbox Mode is that you don't have to deal with all these pre-defined storylines and so on. You will just pick a location and start playing the game without that lousy banner missions. Don't expect them to give you an empty map and add assets. That's also not logical for anyone at all. If people won't get bored with this shallow game quickly, and if everything turns out like in Warband-case, then you will see a lot of tutorials and guides for modding. Then you can actually start doing something if you don't want to get your hands dirty. But don't expect Devs to hold your hand - they can answer some of your questions but no Dev will give you a huge explanation and/or tutorial unless he has a patience like a Saint.
Thats basic stuff any moddable game needs, and the kind of stuff that makes me think they just dont want any modding of their game...
Well, you are wrong, sorry. These are not the `basic` stuff any moddable game needs. I didn't see any Sandbox mode you described in any game at all - to be honest. ( Except in some Atari games where you were able to design your own levels etc but that's not "modding") Most of the games don't even support modding all together and some don't support at the beginning and bringing tools etc after a year or so. Currently game is in EA - this is no excuse for it's lame feature content, but it's an extremely good excuse for not having really easy modding support - which is also something you are mixing up right now. Easy Modding Support doesn't mean Modding Support. Can you have both? Yes - but this requires triple amount of work. So currently what they are doing is totally okay.
tl;dr: Game is 10 times more moddable than their previous game ( codewise ) and they are also providing modding tools - even though game is still in EA. That's not as easy as you think. If they keep everything same after release + 6 months, then you can continue your roasting by saying that this type of modding support is just hard and messy. But currently, stating this is not right.