Other problematic NPCs are those near doorways and in narrow passages, who can eventually block your travel into and out of the area (Ranis Athrys in the Balmora Guild of Mages being a prime example).
If you save and reload the game, however, all creatures that already exist have their maximum Fatigue set to the sum of their Strength, Willpower, Endurance, and Agility, while their Magicka is set to twice their Intellect. It's not clear if this bug affects all versions of the game. Drain Intelligence to 1 and Fortify Magicka in the same spell will give you large amounts of current Magicka. If you save and then reload a game, all summons that went hostile from being attacked will return to being friendly. 1) Train your enchant skill up to a decent level ($), along with your Alchemy.