Your procedure looks great. Just one more recomendation: use Z6 before your first ZFX+Z2 coat as well.
Yes, it will last 6 months if you wash semi-often with Z7 followed by Z6.
Z5 is overrated IMHO except for dark colors. Even then, I don't notice any swirl cover, just a slightly different look.
Z6 procedure: Spray on applicator, wipe on car, buff off with towel. Sometimes I spray right onto the car, but it uses much more Z6. No need to wait 5 seconds, but no need to burry unless it dries.
Dawn or regular clothes detergent is find. Just no bleach or fabric softener.
If the water blade works great for you, that is fine. I, too, use waffleweave MF towels.
