RoadMap does routes just fine if you're using the TigerMaps provided by the US Census Bureau. (Available from roadmaps.sf.net)

If you're using dumps from OpenStreetMaps.org, then no, it can no make routes.

I don't know about re-routing. I haven't had a chance to drive with it. I suspect it doesn't, but then I suspected that for MaemoMapper, too...

[Edit]This is wrong. Address lookup, but no routing. Sorry!