If you know all this, why did you post a thread a few days ago about how barrier is unbeatable?

Maybe this needs some more concrete advice, but I think it needs things more in the form of:

"From level X on, you should be able to get a potion of return in five minutes. If you can't do this, this is a goal for you to work on." This is implied by my saying that you should be able to come up with that plus several things more as a ghost from nothing, but it might not be obvious enough.

Essentially, you're playing a game against a bunch of people for whom getting any number of return potions in a short amount of time isn't even something that requires thought. There isn't some secret unified way to do this, and I bet if I asked ten different players how they do it I'd get at least eight fairly divergent answers -- but it's a problem that most players have solved, and until newbies have solved it (and some of the others), they are forever going to struggle to compete.