Q1. Interested, but not sure if I'll buy one now. Half a year ago, before I bought a logitech USB wheel + pedals and a pole position gas pedal assembly, I would have. If the price is nice, and it's a high quality assembly, I'd get one; otherwise I'll probably BMO.
Q2. Analog, but that's a given for me. (hint: analog+

) The switch others have talked about would be nice, but not needed or planned to use for me. Gameport would be okay, but I'd choose USB or that if given a choice.
Q3. How about just the pedal assembly, and assembly with the pedal bay as an add-on? I think I'd just get the assembly and build the bay myself, but not sure on that.
Q4. I'd prefer both gas and brake.
With the following output: combined gas & brake on one axis (gas -, brake +), only gas on the next axis, and only brake on the last axis. (or combined on Y axis, gas axis 4, brake axis 5, but that's just for a "more "standard" directX setup, not important).
I'd like a clutch, too, but that's not all that needed for me, so I won't pay much more for it
Q5. ~$25 for gas only, ~$40 for gas & brake, ~$50 for gas, brake & clutch, give or take a few $s.