My Character is not a mage but a warrior. But from your post i think that would mean that the regen of mana does increase. Meaning that if you have 100 mana and if it regenerates in 60 seconds and if you have 200 mana and it regenerates also in 60 seconds...does that not mean that the amount that gets regenerated per second is increased? And as such make the regen of mana faster the more mana you have?
That's not how it should work.
1) Your magicka pool would take (e.g.) 60 seconds to regenerate - unless the % regen is changed
2) This is consistent whether you have 5 magicka points, or 5,000
The regen bonuses (e.g. 100%) should mean that it would take less time for it to regenerate. That's always the way it's worked, and it's how it works in this game - out of combat.
The difference is, when you're in combat your pool regenerates MUCH slower. I don't understand why