Here are my experiences for those interested.
It turns out that MMM and OOO don't go well together (without downloading something else and setting that up...). So I went for OOO and some other smaller mods like unofficial patch (conflicts with OOO but I don't care anymore), Stealth overhaul (seems to make my regular hotkeys mixed up), Elven map (can't remember the name - but if you use it you have to change your oblivion.ini to make it work, found out after some swearing at the screan that RTFM works), Phinix dark UI (no real problems with this one actually!) and a time scale changer to make the days longer. And I also added the FREE Fighters Stronghold from Bethesda (free until sunday that is).
The game in itself is beautiful, and a lot of fun. The mods should expand on this and I think they probably do. I'd reccomend only using a few mods though or you will drown. The fact that the hotkeys from Stealth overhaul 1)don't work half the time and 2) disrupt the regular hotkeys makes me want to remove that one. Only it's fun to shoot enemies from where they can't see me
Maybe I'll reinstall and only use OOO and a couple of new mods like Fighters Stronhold. I fear that my repeated modding makes the game unstable. Haven't had any ctd's yet, but it gives me an error each time I exit.
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