I think you could do a lot worse than just getting the right tires and fork for your Trek.
Skinny - but not too skinny - tires, rigid fork (I just put a Surly Troll fork on my commuter) and go from there. I am in a very similar state of mind to you. I used to have a Sinister DNA DJ bike that was by far my favorite bike that I've ever ridden (it was stolen). But I really like the idea of having a bike that can jump, manual, drop and whatever while still being quick enough for my commutes. I've been looking at different options, the new Santa Cruz Jackal is basically the successor to the DNA with the same sort of adjustable vertical rear dropouts, and although I think its HA is too slack, I wonder if it is possible to have the right seatpost and bars configuration on one of those for them to pedal well over long distances.
Right now I am just borrowing my SO's 2007 Kona Fire Mountain, fitted with skinny 26" tires and a rigid fork. Geo wise I don't think it is all that different from your Trek, and I bunny hop curbs and puddles and what-have-you all the time. The only thing that is really holding me back from doing anything too crazy is that I have a rack on the back and the weight of my stuff on the back (and sometimes the fragility of said stuff). So overall it is quite adequate. If I were to switch to a backpack, I could do more.
If you wanted to jump more than just curbs, the seat (if it is in a proper pedaling position will get in the way, so one solution might be a gravity dropper or other on the fly height adjusting seatposts.