-Allow for "half" health so that taking an odd number for endurance is viable
-Have the rate of AP regeneration static, the same for all levels of agility. Agility thus allows a bigger initial blast, doing 2-4 attacks in a row immediately. For whatever reason, I associate this with 6pool zerg rush if that makes any sense...
-Alternative to the above, intelligence determines AP regeneration, while agility determines total AP potential. Thinking quick on your feet for intelligence, compared to quick initial reaction for agility.
-Intelligence determines the perk rate. Very radical, would highly suggest adding in more and rebalancing perks in general though. I think it is a really cool idea if perks could be overhauled in general.
In general I would like to see the necessity of agility reduced, without increasing the tedium and amount of time "waiting." If AP were split between agility and intelligence, I would highly suggest a slight increase to both, with 10int giving slightly faster AP gain than 10agility does now, and 10 agility would probably give slightly more than 10AP total.
This is all radical change though, and even I'm unsure if they're any good. But its out there for others to judge, consider, and inspire possibly.