I'm theoretically a Battlemage but I don't use magic much these days except for light and healing.
Now the only problem is really the weapons are a bit TOO powerful. One wrong swing and I take out Lydia. She can survive one blow but not if she is already injured. I have to be SO careful that I'm debating leaving her behind next time. Maybe I should just give her a superbow instead of hand weapons.
That said, I'm actually enjoying exploring Blackreach. So far I can relax and just marvel at the really cool sights down here. It's been a lot of fun. In the beginning, my lack of fighting skill meant I was getting killed all the time by most things. I much prefer it this way. I may be too overpowered for everything, but we'll see because I'm back on the main quest and I'm headed (slowly) for Alduin. I didn't really believe it when I read on this board all the stuff about smithing/enchanting being a bit too effective, but so far it's hard to dispute. But it's fun!

and light dragon armor
it's hard I know...