Chris, if it helps I'm relatively new to the MR (3 trips in 3 months, 14 parties, I think I'm on pace to catch up to Cobia in a thousand years), so I know how you feel.
It's an unhurried atmosphere (p.s. and no smoking - yay). Get a drink at the bar, smile at the ladies, don't ask for a lineup unless that's really your thing. If you don't approach a lady, one of them (at a time) is likely to approach you after a couple of minutes and make smalltalk, assuming you look reasonably presentable and clean
Always offer them a drink. If you're not interested after a few minutes, very politely say that you'd like to talk to another lady.
The ladies are super classy, will sense your nerves instantly, and are willing to wait for your nerves to settle. (If not, find one of the 99% of Mustang ladies who won't rush you.)
There are no fixed costs; it's all negotiations. A typical party is 1 hour, but if you are low on funds, the negotiation might compromise at 45 minutes, etc.
You asked about safety. It's squeaky clean and regulated to hell (in a good way). No worries. None.
And don't think of it as "crossing a line" to use your phrase. This is the perfect place to improve your confidence - and infinitely better than a drunk quickie!