I have 100% cpu depending on fps, which is normal. I have put limits on fps, from 60-200. I don't use realtime for vsync either.

I give the user the choice as to what fps he wants. Most games I know of, however always try to take as much cpu as they can to ensure max framerate

With 60 fps, cpu usage is as little as 10%, and with 200 (interval of 5), it goes to around 40-60% [pentium 4 2.8 GHz]

I also use threaded timer but I aint the expert around here by a long shot ops: but in my own opinion, super high framerates/realtime are not necessary most of the time. For example, even with 200 and vsync (the monitor will obviously refresh at its max framerate, to me that is 85 Hz) I get a totally smooth game.

Experiment with the FPS and make it suitable to YOUR game