The only problem I see with setting afternoon temperatures higher is it may be a no-sun day and your system cranks away to reach 'sun warmed' temperature, and the higher temperature will induce a stronger chimney draft effects so proportionately increase leakage and thus cold air infiltration. If the house wants to warm up in winter time think of it as a bonus but don't spend money reinforcing the trend.
Here in Minnesota if we open the south window blinds up to capture as much sun as possible we end up with three warm sunny rooms and five frigid rooms since the thermostat gets fooled and no air circulation occurs with forced air heat. I know it's just this floor plan, but forget to shutter up after the sun goes down there is serious chill climbing in with us.
On the long firing times from setback recovery I agree with you. This year we raised the setback point from 62F to 65F and have seen a probable reduction in overall gas usage, maintaining the 65F overnight means overall shorter run time than the daily hour plus run to bring temperatures up suddenly. For the 30 day period ending mid-January the average temperature was 12 degrees lower, gas used was just 13% more than previous January for additional 40-cents daily cost with $141 gas used, for 42 daily average heating degrees versus 30 prior year. We were very surprised - nothing much else had changed in terms of insulation etc..
Opening the house up and exchanging air with the cool of the morning works good but in the hottest parts of summer twilight is over about 10PM and that is about the time the suns' heat load becomes most apparent - the heat has worked its way through the insulation and roof & walls and must be dealt with then if there is to be any peace in the house - no matter what happened 12-16 hours before. Programming to use power to cool in the mornings may not be needed if it is overcast or rained, the thermostat can't tell that.
