I bought this games some time ago in Steam, is there any major difference to the content in here How easy is to progress, I remember when the game was initially released, that it was really easy to fail because it was almost impossible to earn enough and to progress you had to pay for higher Patreon levels to get the "developer" version, it still happens?
Do the walkthroughs and gallery unlockers works with the Steam version?
The last bad end event I can remember was in the Rastedel arc, which has been complete for a while. So walkthroughs should be fine no matter if you're playing Steam or Patreon. Though the one labeled "Walkthrough" (that's just a listing of scenes and how to get them) often isn't updated for stretches. I have no clue if it's currently up to date or not, or being continued or not. Or who even made it.
The Extended Scene Replay Mod is...potentially more complicated. It should work for the Steam version in general, but I could see there being issues installing a later version of the patch on an earlier version of the game. Since the Steam version updates every-other Patreon update and MonkOne doesn't keep the previous version of the mod in the post, there will be times when the mod is functionally for one version of the game higher than the Steam release. You'd have to try it to see, but even if it messes the game up, it'd be pretty easy to uninstall the mod one way or another.
I think the mod's intended version and the Steam version are currently aligned, but once the new update is released and MonkOne updates the mod, this would no longer be the case. That said, I don't actually play my Steam copy, so I can't verify the timing.