Heater question?
#3
Check to see if the heater core is plugged, run the car up to operating temp then grab the heater hoses, they will tell you alot. If they are both hot its an issue with air distribution such as a broken heater control cable or blend door. If one is cold, One is hot then check for a plugged heater core. And if they are both cold then I'd be looking towards a t-stat or not likely but maybe a waterpump. Hope that helps.