I've been to the strip club more times than I should in the last couple years, and you're definetely right about the "best friend" thing. I talked to some of these girls and got to know them a bit, and almost every time they have a friend at the strip club that they swear is their best friend and not just a chick they can talk to at work. Then within six months they're not talking at all. I've never asked why, but I'm sure one of them did something grimy over money, drugs, or a dude.
I can think of at least one stripper I've met that seemed to treat things as total business and didn't seem grimy. She didnt try to convince me that she really liked me for real, told me exactly what would happen in a lapdance and what she'd be OK with, and that was it. She was a legit 9 or 10 and can probably do that, put herself at a lot less risk, and still make good money. A 6 might need to lie, backstab, and do a lot of grimy sh1t to make the same money. You can't trust a stripper thats a 6 at all.
Some of these girls are straight evil, but some are more just bummy. They get money, spend it stupidly, and cant hold a real job schedule, but are bummish and flaky more than straight evil.