I've used a file or angle grinder to de-rust the edges of spinning rotors. Just let it idle in 1st gear and try not to get caught by the wheel studs!
When my neighbors got their 2007 Fit, the A/C didn't work. I charged it and it worked great at least until they sold it a few years later.
The valvetrain isn't hydraulic, so I wouldn't expect any rattle.
I love the Fit handling!