NO, You are already way overstocked, and a 30G is not sufficient for a Yellow tang.
SO...IMO the yellow tang should be rehomed.....The lawnmower blennie will probably starve to death, so you might want to consider getting rid of it too
a maroon clown is very aggressive...especially in smaller tanks.....so the PJ Cardinal, and 2 chromis should be okay
MAYBE...if you are on top of your tank you could keep the 2 YT damsels....BUT I don't know that I would (maybe 1)