IME, you'll get a few months out of it no problem. 5-HTP, staying hydrated & making sure you eat reasonably well over the weekend, not smoking much/at all in the week, plus the other things you said, in most cases it's not going to do anything terrible to you, and yeah, you'll manage it fine for a while.
Then the comedowns get shittier (physically, i found, not mentally), you spend all weekend being a zombie, the pre-roll anticipation gets really harsh, and the magic starts to go. I don't think there's any way you could roll every weekend indefinately & not have it turn to shit. (but i can't deny that absolutely caning the honeymoon period is a LOT of fun
)
Even now i've cut down massively on the amount i do, i'm still FAR more of a mess on Sunday than anyone who's newer to it, my tolerance is still pretty huge, and the magic can't be relied on (although it has definately come back to a large extent, it's quite reliant on set & setting), although the pre-roll anxiety has improved a lot.
I think without taking a 6 month+ break now though, there's no way i could go back to weekly use without really fucking myself up