For problem #2, have you looked at your frame limit? Sometimes, it can do that based on the fps your pc runs and what osu! is running.
In regards to the maps loading, check your local files and ensure there isn't any programs running that could potentially be deleting your maps.
The fps are always at 240 (unlimited) the ms doesnt go higher and I dont know any program that can delete the maps.
how to get "unlimited" fps:
1. open the osu! folder
2. find "osu!.(pc name)
3. open the file in a text editor and find "CustomFrameLimit"
4. set it to some number like 69696 or 2000
5. save your changes
6. open osu and see the stuff happen
You mentioned "updating drivers" but you didn't mention which ones. If you haven't tried reinstalling your audio drivers specifically, you should do that.