From what I know:
1) If by "batteries" you mean drums, it depends. Rock Band 1 drums are wired, so you plug them into USBs and it's done. If your talking about the one built in Rock Band 2 or Beatles bundle, they are wirelees. You may plug the RF-usb adaptor into your console, plug the batteries (remember, it's wireless) and then set it up to connect. It's very easy, so don't worry about that.
2) It comes with one mic and it's standing. There is a deal in game.co.uk where you can pick the game at 39.99 GBPounds and two official wireless singstar mics come for free (that's a huge deal if you ask me LOL, I preordered =) )







