Would
Yes probably would cycle to fast and not dehumidify well Dehumidification works best with a cold interior coil, a 25 degree split or more. Slowing the fan will help dehumidification but a colder coil works better.
Hopefully someone from alt.hvac
You do not mention the sqft/cubic feet involved. Zoning a/c is done in my area for only the extreme rich. It adds a level of complexity for the project that a lot of installers are not accustomed to.
Are your walls between the zones insulated? If not then there is little reason to add a lot of complexity. Do you have supply and return ducts in for the zones?
Listen to your installers and choose the one that makes the most sense. I think your trying to trip over a penny and will end up will dollars flying out the window. According to the link supplied your looking at ~400 hours annually for cooling. Where I live it is more like 2000 hours. A high seer unit installed by a good contractor with some performance numbers after the install and you will be money ahead. IMO http://198.147.238.24/ac_calc/default.asp