1) You can use it with a brake. It's designed to be a dual-purpose road/track wheel. It's heavy as sin (though not as heavy as those ******** aerospoke wheels), and often times the hubs/bearings/threads have problems, so ride with caution (that just means check the skin, and thread semi-regularly).

2) You would be perfectly fine using a suicide hub on the track (unless we're talking about match sprints). You basically never apply enough backpressure to unthread the cog. In fact, a lot of people take old 7sp freewheel discs, put on an adapter (that basically spaces the cog out farther) and ride those.

3) If I got that for under $10 and didn't really ride on the track, I would ride the sht out of it on the street. Don't let peoples' pansy fears keep you from riding that ***er like you stole it. Even in a crosswind, your rear isn't going to go sliding around that much anyway.

Congrats on the totally rad buy!