PDXHatchback

OK, First things first, I swapped an OBD II GSR Motor into my 95 Hatch, swap was pretty simple however, since then I have not had any heat.WTF? My heater is blows out winter air man! Freezing. Also, lately my temperature gauge sky rockets then once I slow down comes down slowely. (takes about 15 seconds to come down to normal. I have no idea what is causeing this. I just replaced the thermostat and of course that wasn't it.
2nd problem.

My car has a really bad erratic idle. It revs between 1000-1600. After the car gets warmed up is when it starts to happen. What could that be, I have been trouble shooting this for a while and still nothing. I really dont want to have to take it to a shop but this is my last resort before I do. Can some please help me and save me a lot of money???

Thanks so much for your time and patience,
Joshua