Now mods that stop health regen, for the most part, work. The only thing the default Health regen do is avoid using Potions/spells to heal you up, and pretty much negate the value of regeneration potions and renting a room at an inn.
However I was curious as to your take as to halting magicka regen. As the game stands balance wise right now, it would be terrible. Please don't get me wrong, I could very easily just go in and turn off magicka regen in about 20 seconds (well, not including the massive front loadtime of starting up creator kit). And in a few minutes make one that works well(ish)
But for people who want an old school experience (ala: D&D, other old games) wherein you have a limited number of casts (or magicka) inbetween resting you are pretty much screwed. Sure you could turn off magicka regen but unlike health, it would make mages practically unplayable as currently their spells don't do much damage.
So really the alternatives are, reducing spell costs across the board or boosting the effects of current spells... or both... or something I haven't been clever enough to figure out.
Really I am just up for anything that makes inns more useful... I haven't made a septim from adventurers in a long time..