What if I expect to explore most, if not all, of Skyrim with one character? How do I achieve this without gaining a high level?
Same way I am. If your weapons and armor are already maxed, how are you going to level from fighting? You can explore all day long taking hits and hitting things and never gain one level point. If that is what you want. If you use skills you have not maxed out, then you will level some more. It is all in what you want. I have only gained two levels in the past week of playing, and that was because I was re-charging my enchanted sword and picking some locks. Those skills are still in the 60 to 70 range.
I am not worried about it as I don't care about my character level, it means nothing in this game, only my skills do. Sure, there are some quests and enemies that unlock at certain character levels, but my character will get to those levels just by playing the game. And, as long as my skills can handle what I am doing in the game, I don't worry about what level they are at either. I find it quite refreshing at this stage to no longer have to worry about character development, I can just enjoy exploring and questing.
Now, my character that I am going to start this weekend? I am going to worry about their skills for a while as they will be fresh off the cart. But, that's what you do with kids, worry about them and nurture them until they are able to take care of themselves.