Keychain style flashlight or headlamp, LED type, not incandescent: The keychain style is tiny and lightweight, the headlamp style is a bit bulkier but easier to use. You can get these for a couple of bucks or less at the local big box hardware store. The LED ones are lighter, more durable and last considerably longer. Very useful if you need to make a repair after dark! I keep a keychain style one as a backup as I normally have a headlamp in my backpack.
Based on what we found, we chose the most relevant items and used them all. To test patches, I repaired holes using four different types of patches, from Novara (REI’s now-discontinued house brand), Park Tool, and Rema. Patching a tube isn’t hard but there are a few tricks, and the key was attention to detail and patience. I was extremely diligent in following proper patch procedure, which includes a thorough sanding of the entire area to be patched (for max stickiness) and properly letting the vulcanizer dry on both surfaces before applying. For the peel-and-stick patches, I went so far as to prep the area with canned air to ensure as tight a seal as we could possibly muster.
Modern bottom brackets use a sealed bearing type construction that keeps water and debris locked out, so they seldom go wrong. Maintenance is impossible so they need replacing when they do wear out. Older style cup bottom brackets need to be re-greased every now and again, and occasionally will need to have their bearings replaced. There are a lot more teeth on the chainring cogs than those on the rear cassette, so need changing less regularly. Cranks usually a solid one piece construction so there is not much to go wrong.