I usually prefer the atronach stone on melee-focused races that are absolute trash at magic (orcs, redguard, nord) because it remedies their big weakness which is low base magicka. As far as magicka regen goes, those races have pretty bad magicka regen too so the penalty isn't felt quite as hard. Stock up on health and magicka potion if you plan on dualcasting costly spells and using transmute blood, helps in the early game but they aren't needed later on once you get weapons that absorb magicka or health, like mace of molag balls, ebony blade, or you can have an enchanter enchant a weapon for you if honed metal suits your fancy. As far as magic schools go, just use whatever suits your fancy, but I wouldn't recommend healing auras with transmute blood.