it is a honeywell pro 4000. The system does have a zone panel...does that mean we don't need the 2 stage tstat? Or, will the 2 stage tstat provide better control even with the zone panel?

Lastly, I've seen that honeywell has a stat that appears to allow you program fan speed...will this help us solve the problems?

thanks in advance for all your time and suggestions over the past 2 weeks.