How much is a little play? You always want some - if there is no play at all, your chain is probably too tight.

You're much more likely to have a high spot/uneven ring if it's stamped instead of machined. I had this problem on the bike I built friday - switched out the chainring with a Rocket ring on saturday and it's all better.

Instead of pulling the wheel back, I usually push it back, standing inbetween the front and rear wheel. Tighten the drive side first, not caring if it's exactly centered, and not all the way down, just enough to hold it. Press on the chain, should have 1/4 to 1/2 inch up down in the center. Add another twist to the drive side, then center the wheel and crank down the other side, really tight, keeping back pressure by leaning on the wheel. Check chain tension again, if it's slackened, I loosen the drive side and push it back - it should move to the point it was first tightened, and center the wheel. Sometimes you have to repeat a few times...

Hope that helps some.