How are Emax quads?
 I was looking at some BNF quads and baby hawk pro 4” 3 has made improvements.
  I have had experience with Emax years ago before quads and it was low quality.
  Quads and FPV has changed the RC market so maybe Emax has improved quality or is it still clones of higher quality gear?

Emax has above average quality. Do hesitate to buy.

It might be too fast for a first quad.
I’m assuming using exponential and dual rates the controls can be used on quads to put limits on how fast it goes and roll rates if sticks are moved to extremes,but since everything is controlled by rpm of motors I can’t use tx to set exponential rates,I’m assuming it’s done in Betaflight?

Can a freestyle racer quad be dialed down by using expo,dual rates to limit speed,pitch,yaw and roll sensitivity,etc.. ?For planes we just adjust amount of travel by using dual rates or changing end point values on tx but with quads I don’t think that’s going to work.

Yes you can set all the rates and throttle limit in betaflight. Check out joshua bardwell on youtube. Another great resource is the uavtech youtube channel, more technical but very valuable.