Painting Galvalume Metal Roof

Hello. I had a conversation back in 2004 w/Todd via a blog thread that is now closed (https://www.metalroofing.com/spirit/topic/1105/best-paint-for-galvalume/). Most of the links in this thread are now bad, so I thought I'd start over since I finally plan to paint my 22-yr old Galvalume (9" G-rib) roof before installing solar panels. I had its screws replaced last fall (Oct. 2021), using the new and improved screws whose rubber gaskets are protected via a metal shroud. From what I can glean from said closed thread (and other recent Google-based research), I'd need to:

1.)Wash (gently scrubbing) the roof w/something like TSP; rinse. Dry.
2.) Wire-brush the light rust on the ribs & any other rust spots. Dry wipe rust residue.
3.) Treat rust w/rust converter (e.g., Loctite's "Extend"). Dry.
4.) Apply an all-in-one etcher/primer. Dry.
5.) Apply a 2nd TBD primer coat (but not of the etcher/primer type). Dry.
6.) Apply TBD top coat (possibly two coats).

A. Can I skip step 3 if I use an all-in-one etcher/primer?
B. Should I use an etcher primer made for Galvanized & Aluminum, or use some other product(s) combination?
C. I've read where one can etch using a solution of 1-part 5% acidity vinegar and 5-parts H2O. Does this really work? If so, can I assume that one would have to get the primer coat applied before any rain ruined the etch?
D. What type(s) of paint (e.g., enamel, latex, acrylic, etc.) should be used for the 2nd primer coat?
E. What type(s) of paint (e.g., enamel, latex, acrylic, etc.) is best for the final coat(s), and is it dependent of what paint type is selected for the 2nd primer coat?

Thank you VERY much ...
Mark Diehl - Cumberland, MD