Any question answered...

the rear pannier rack on my occasional commuter is getting very worn down. Thinking of giving it a respray to make it look a bit nicer.
Are there any recommendations for spray paint that'll do a nice job, and not be too flaky. Expecting wear to appear again, just slowly.

I'd get a can of what the graffiti artists use - good value for money, nice colours.
Belton Molotow Premium for example (satin finish), or Montana Hardcore (glossy).

Sand lightly, then apply two or three light coats of paint 👍