Answers

73-79 when active in home. This can go up when everyone is at work or school.

Set it where you are most comfortable as that is why you have it.  A good idea is to update the thermostat to a programmable version that will run the A/C mostly when you are home and according to your schedule as well as at the desire temperatures.  It isn't necessarily recommended to shut off the A/C on warmer days when you are not there as it will have to struggle to catch up when you turn it back on.  This would be due to the warmer air in the home and the storage of heat in the walls, ceilings, floors etc in your home.