You may be like my MIL, able to see chromatic differences in colors - I'm not that guy. I can't do it so I use the black/white mixing crutch to darken/lighten. If you can find the correct color needed to get you closer, go for it. I only recommend white/black because it's what I personally use.

That's effecitvely what I do. Knock down the high spots with 600-800, then 1400, then 2000 (wet sand). Then take a buffing compound (just using my finger, buff out with a cloth), then a polish (same, finger, buff), then sealant wax using normal applicator and terrycloth.

For the guides, if you can live with it, zip-tie or the plastic cable guides that come on cheaper bikes for a few weeks if the weather where it'll be is warm, above 70, which I know it's not right now. You can probably get away with rust remediation and using a basic clear there.