I had my wheels off recently to do my endlinks. I noticed the drum on my DS rear brake wiggled some w/o anything else moving. Rotation as well as in and out. Could that contibute to brake pulsing? Do I even need to worry about it?

Hrm, did you try to beat on it with a rubber mallet to make sure it was on all the way? It may contribute to brake pulsing, as I readjusted my rears and it cut down on braking vibrations for me. Remember the rears are only responsible for ~20% of your stopping power, so it doesn't change a whole lot when you do something to them.

Drums can get hot and become out of round. Will give you a feeling similar to warped discs.

They should be tight though when you have the wheel snugged down....Just like your rotors.

Oh, I'm sure they are tight with the wheel on.