Oh - and there's always a problem with learning the "crappy openings", that you'll end up getting over 2000, 2100, 2200, and then assuming you're known as the "e4 Nc6" guy, it allows your opponents to prepare very specifically, and may end up with the opposite effect from what is intended.
That, and the artificial ceiling that you'd end up with - the mechanism for example if you're a Budapest Gambit player exclusively that your rating will peak at 2150 maybe, where you're actually a 2250 player.
4.b5 is a tricky move there. I would edit your post to write what you actually mean.
Regarding the general area of "crappy openings", they're not as crappy as you probably think (though they are not best), and if you're well-prepared with master games and engine ideas, I say go for it.