Scenarios are random by design. Read the descriptions, usually it says why something is off.  Skirmish and Random maps are consistent, unless you choose a map with very few resources. 

Sometimes its very hard (impossible?) in medium and sometimes the AI seems to do @#$% all and is destroyed easyly. Am i missing something? P.S. playing the scénario maps

Interesting idea, I've thought about doing something simpler like a repository on Github with the main folders, e.g., at least a civ, a range unit, a melee unit, etc... Something that would help those who are really starting out, but I ended up putting it aside, the learning curve is quite steep after a while.

I think it would be cool/nice if there was a mod maker gui, so you can easily make mods: add new units, structures, techs, etc. I started making one in Godot, but we could make it in something else, if anybody would want to help that would be great!

Thanks for the report! We have an opened issue for that: https://gitea.wildfiregames.com/0ad/0ad/issues/8876. I want to fix the image in R29. Though the camera will be still "moving". A possible workaround for now is to set the resolution scale to 100%.