2002 Blazer

Hi, I have a 2002 Blazer Electronic 4wd auto. I've got two questions. 1. When going around a corner at low speed my front tires squeal a bit, inflation is correct could this be a caster-camber issue or just a 4wd thing? Transfer case is in 2 hi at the time. 2. In the warm weather with my heater control on cold and the right dial at off ( the one that selects def. ducts, heater etc.) there is always hot air coming from the heater duct on the floor, extremely hot on the passenger side. The only way to get it to stop is by putting the right knob on defroster, then cold air comes out of the heater on the floor but the air conditioning is on then. (compressor running, wastes gas) :( Thanks in advance for any input! Mike