Two questions:
1) my tranny CV flanges have about .010" end play (in & out), is this normal ?
2) what happened here, the other side isn't like this;

Click to view attachment
The CV joints look fine as I had cleaned them previously, just got the the tranny today.
Some former CV joint puked here I guess
Do I need to take the die grinder to these gouges, or are they far enough away from normal movement not to worry about ?

Mine had similar looking wear marks. Not this deep. I wondered about this myself, then I moved on. Again, not as pronounced as yours.

I would be curious to hear the expert opinions... something is moving.

Play is normal and a worn CV had been beating itself into the stub, should be OK.