I don't know if you can make fatigue potions in Skyrim but they help at earlier levels using melee, you can make them easy too. With Melee I just move back and forth, it is easy when you get used to it. As for the mob leveling in Oblivion, they do level with you, but I am level 21 and can smash most things to bits. They have a slider in options though if mobs are to hard. Even as a fighter sneak is always your friend.
Currently 124 hours into Oblivion and I still haven't finished everything.
Like I said in my last post, balls to oblivion for a good 8-10 months.