Frequently, opening traditional Japanese blades requires moving a lot more metal than you can do with strops loaded with rouge.
Polishing on a strop is all well and good, but you're proposed stropping methods ARE POLISHING (and perhaps truing), but NOT SHARPENING. From your description of the blades' condition, they need actual sharpening and perhaps profiling.
I've never used an Edge Pro, or any other tool and jig setup for that sort of chisel edged profiling. I've heard some people say "yes" about the EP and others say "no." Given that the EP is your go to sharpening method, I'd certainly give it a try -- sharpening the front bevel at the factory set (if there is one), or at about 10* if there isn't. If you're using an Apex instead of a Pro you'll have to block the knife up in order to get an appropriately acute angle. I'd sharpen the back bevel just enough to chase the front bevel's burr.
FWIW, I don't think I'd take the deba past 3K; and as far as I'm concerned polishing it to Mother's is just a time waster; all looks and no action. It's probably overkill for the usuba too, but what the heck the usuba occupies a very different niche.
If you can't establish good edges with your EP you're going to have to move to stones. But there's no reason you have to be the one who opens the knives to the appropriate angles. This is one of those times you might think about sending your blades out to someone who really knows the drill for those sorts of edges; and perhaps send the Yanagiba along as well. Who you choose might have something to do with your location... or not. If opening isn't something you're going to do often, it might not be worth the investment in time, seeking advice, and equipment. Your call.
More FWIW: Shaving arm hair is a lousy standard. Even thumb-dragging is a better test.