Mmm, just to be clear meta != no heal
At least, in my own definition 'meta' means competitive in the most updated environment. Yes in quite a few cases a full frontal dps set up can help you end a fight, steal mvp or squeeze into higher rankings, but in a scenario with mechanics where even those space whales beyond our dimension can get screwed over, there's nothing wrong with bringing a healer/cleanser/tank or two to extend your dps cycle. Your dream team can only be as meta as your grid allows after all. So please, if you ever find yourself chewing on more than you can swallow, please do yourself a favor and bring more recovery and/or mitigation.
Anyway back on your question, what do we do in multi-stage contents? It's quite simple actually. Emote for a free potion L in Rag raids. GO otoh simply drops exactly 2 small and 2 large potions across the Wave 1 (S), 2 (L), 3 (S) and 4 (L). If you're still struggling though, please bring a healer or tank. In AQ5, potion drops are random so if you find yourself struggling please (again) bring a healer or tank. As for Tower, this hell hole is not for discussion. First 10 floors are ezpz. But 11F and beyond, please double check your team and your grid and carefully judge whether you are up for it. Do not try to be the (dead) hero.
I don't like the hp bow myself because just as you already answered yourself, I lose out too much on sustained damage on everything that isn't PF burst. However, I do acknowledge its merit in BT MVP stealing. Basically the idea is you sacrifice a significant % of your basic damage for a one time big number MVP steal. It's totally up to you whether you want to try it.
Hmm. 30~35k SR team is a cutting it a bit too close imo. The SR runs videos I did all have 43~45k attack and I find the pace for those just a little above comfort zone, so I would recommend 40~43k average attack on top of having at least 9~10k in battle hp for your hime to be able to clear GO missions and AQ5 at a reasonable speed. These are chores that you will be grinding almost every single day so you don't want to struggle with them every time, it just kills motivation.
i.e. casually and poorly assembled set up I did:
youtu.be/Lx6AEVyBpxE
Plenty of mistakes here and there. Failed the all member alive mission too. But overall not too terrible as long as you know what you're doing.