ShootMe was removed from the market by the dev. He started getting hatemail from people who were too stupid to read the description of the app and didn't realise what root access was. A shame because it was one of the best screenshot apps out there. You can take screenshots with the SDK or MyPhoneExplorer though.
Rom wise, it depends on what you're after. LeeDroid was pretty good, but as far as I'm aware, he's got some stuff going on at the moment so not sure if that's going to be supported in the short term. Sense wise, you're probably best to go with ARHD.
As D-U-R-X mentioned, CM7 is a pretty good option if you don't mind losing some of the Sense stuff.
If you're just looking to freeze/remove bloatware, make sure you take a backup of a working ROM in clockwork before you do anything as there are some apps that when frozen/removed will prevent the phone from booting.