I previously owned the 803D - it still a great easy to listen loudspeaker. Re your questions:
1. auditioned 802D a few times - more open midrange, bigger bass not as well controlled as 803D. So for 802D recommend choosing an amplifier with reputation for tight bass control.
2. visual expectation for checking drivers in perfect order. Kevlar midrange tends to go darker and more orange as ages, but accelerated by exposure to sun. Check for consistent veneer colour for cherry wood. Obviously listen to loudspeakers - make sure you like what you hear, but understand dependency on gear driving the loudspeaker.
3. I drove the 803D with 60W amplifier - quality and good current capability more important than watts. At simplistic level, solid state amps that double watts from 8 to 4 to 2 ohms indicates good current capability.