I just switched to a 1x8 this last weekend...already threw the chain! Definitely get a Bashguard, and if you're savvy about it you can do a bashguard on the inside AND outside. There's not room on my Xcheck for one on the inside, so I'm going with the N-gear Jump Stop on the inside and a BBG on the outside.

I've got mine set with a friction DT shifter...I like it that way, and since I was switching from flat bars and I have v-brakes it was the simplest and cheapest solution.

Make sure your chainline is good...as in the ring is in the middle of the cassette.

you definitely don't need a new crank, just put your desired ring in the middle position. I'm runnin' a 42T with a 12-28 cassette and a vintage XTR rear der.

Have fun!