Lighting is fine, Mushrooms are good etc.
Note that many of the weedy noxious reef algae that many do not like, are useful for a planted marine tank also.

Plant the layout good.
Fining good algae is tough.
Everything needs shipped next day, the shortest transit possible etc.

Skimmers and macros really do not go together as the skimmer will not make much foam when you have macro's.

An entire debate exists there between skimmers and macros, but macros are pretty, look better, fish can eat them etc, but skimmate foam?

Skimmer may act as back up in case you kill off the macros.......

With water changes: you can never do too much.
Dosin is not needed that much if you do the water changes other than KNO3, good feeding, Traces/Fe.

PO4 only if you go full out have a lot of growth, then only small pulses.
You'll get diatoms bad if you over dose PO4.

I did weekly 50% water changes.
Not that cheap on larger tanks.

Regards,
Tom Barr