Can you swing / randomize hits?
As was stated, DFH (Superior, in my case) is a sample kit; it does not include the ability to play patterns, only single hits driven via VST or ReWire.
Does it provide waltz time and odd time capabilities?
Nope, due to the above reason. However, w/ a good drum map you can do any odd time you would otherwise define in the Sonar project.
Can you select stick vs brush vs rutes, etc?
Yes, DFH does have that. You select each drum in the kit and that's based on sticks, brushes, felt, etc.
How adjustable are the dynamics?
Pretty good w/ DFH, though I haven't worked out the velocity curves exactly like I'd like in each situation. As I understand the manual, various velocity levels will trigger different samples for the same drum. You can adjust a minimum and maximum velocity, ambience, microphones, etc. The only downside is the way it maps back into the project via VST, but you can get a lot of control using the Sends technique that's documented on the Toontrack website.
How realistic are the fast patterns (rolls, flams, fills)?
I'm no drummer, but they're more realistic (I think) than the hits from any of my other gear (Alesis SR-16, QS7, or Korg Triton Rack). The key, at least as far as I've seen, is the ambience control; that makes a world of difference for the stuff I've done so far.
How realistic is the hat and ride playing (opening and closing hats, shoulder vs bells patterns)?
The ride hits are pretty brash, but then again like I said I haven't worked out the velocity settings exactly right just yet. The hats sound fantastic.
Can you use your own samples?
Not that I'm aware of. Then again, w/ 35G of samples out of the box with DFHS, that's keeping me pretty busy. Use Cyclone and your own samples if you want to build your own kit.