I would argue that memory slots should be a far more scars resource, with a cap. Having a limited skill pool in a fight (like the ones in Act I) evens things up, regardless of level. This could be complemented with a swapping skill system mid fight, which could come, too, from memory slots.
7 Memory Slots: 5 for skills, 2 left for 2 swapping possible per fight (could be represented as a consumable skill). Numbers would require tweaking.
