Idling - Listen to it purr...
Miata has cold start issues?
when I start up the car it starts about 2 or lower rpm(cold morning) and when I rev in neutral The motor kind of shakes the car, I let it warm up for a bit and goes down under 1 rpm and doesnt shake anymore after about 2 mins of letting it idle down. any idea's? is this a problem?
The car's computer has a fuel enrichment at cold start that also raises the idle. It's normal.
As for the shaking, everything is cold and shrunken. When the oil starts flowing and friction warms everything up, the tolerances go back towards normal.
When you start the car, I wouldn't touch the accelerator for 10-20 seconds. Just let the it get the oil flowing. No need to rev the motor when the oil is flowing like cold syrup.
4,000 rpm - entering the fun zone
Maybe some new motor mounts wouldn't be a bad idea.