Quick questions
 

Recently bought a '79 with a 12a engine out of a mid 80's RX7, just got her running but due to poor tuning and cold weather it idles REALLY high until I finesse the choke and slow her down, but before I figured out how to slow idle using choke, she ran HIGH (tach not hooked up so no exact number but it sounded around 3k or less). Is that terrible for the engine? I was planning on rebuild whenever I had the money, and how long does it take to warm up? I usually let it idle for no less than 2 minutes, drive it for around 5+, and then get a little throttle happy (not insanely happy, just rev it up for a second or 2 every once and a while), sounds good but I feel guilty not knowing if shes ready for it.

It takes a good 15 minutes of driving to warm it up fully. Maybe even longer depending on what you're running for oil and what the ambient temperature is. If you have a working oil pressure gauge you can actually see when the oil bypass valve opens -the pressure will rise significantly but it won't happen instantly. This is a good indication that the car is fully warmed up. If you don't have a working pressure gauge then just wait 20-30 minutes before givin' 'er hell.

It is normal to have a high rev on a cold start. 3k is about what you'd expect to see.

Spend the time to adjust base idle speed and mixture.
pulling out the choke to slow down the engine,is doing exactly that,choking the engine with fuel from lack of air.
This has an adverse effect on housing/rotor/seals as all the fuel is washing the film of lubricating oil from these parts. Pull the dipstick and smell for odor of gas in oil.

If unable to bring idle speed within specs(800 rpm),start looking for vacuum leaks. Any air being pulled into engine other than thru carb throttle plates will cause an excessive idle speed.A large enough leak,the engine won’t idle at all without choke applied.