You can respec at the Shrine of Stendarr. It's 100g per point spent. There is no need to start over. If you want to level skills, you can put points in them and either use them, or just put them on your action bar before you turn in a quest, then change back to something else. I would advise to use a combination of medium and light armor. I wouldn't personally bother with heavy armor much, only to get the skill Immovable which is very good.