dont repaint it, manufacturers use a higher grade paint than you can reasonably get your hands on, also if you dont completely strip, primer, paint , and top coat it'll look awful, and even then the paint will scratch off easily. keep the deraillers, just get some tri-flow from your LBS and lube the pivots. new tires definitely, old tires will blow out. also, skip the fenders and chainguard, they're just gonna rattle and bend and get in the way, especially on a commuter.