Steam Forced updating is exacxtly why I get all my games on GOG, even if I previously bought them on Steam, when they were Steam exclusives. I detest all store client bloat.
I suggest you read that linked thread to discover what I did to rollback.
You are able to do the same, and as an owner, have a moral right to do so, if the legit version doesn't work.
As far as fixing Steam
I assume you've verified the game files.
Long Loading Times are normal if using DOS2 mods, when adding, or removing them.
That causes a rebuild of certain files, which can take upto an hour.
After that first time rebuild, the loads should go back normal lengths.
There are a few reports of loading issues, I've not looked at many, and the ones I have seen are unclear about mod use.
Some other games have used the Steam Beta system for initial patch releases, which allows a rollback to the main build, if issues are caused, don't know if Larian's done that though.
The only other thing I can suggest is trying a save from before the issues occured.
This at least tests if the problems are embedded in the save itself, rather than the game files.
If they are, Larian may be able to fix the save, I think they did that for some with the previous patch, not certain of that though.
Last edited by Uhuru NUru; 03/11/17 11:13 AM.