If you only use one crafting skill it will level naturally. Only when you combine them to exploit the system deliberatly they will be overpowered.

Don't put any perks into light or heavy armor and no matter what your armor is it will practically svck without the 100% mulitplier + all the other boosts you can get (matching set, etc)

I ended up doing this by accident simply because the offensive perks were so much more appealing.

If you want to smith then smith. If you find you armor is too high for you level then turn up the hardness settings. The game actually tells you in one of the opening messages that you can turn up the hardness at any point in the game.
The game has covered this. Just read it and play it.

I created armor and weapons not only for myself, but for my many followers I tried, before I settled down with Mjoll
So I ended up making quiet a few different sets.