In general... are providers alright if you book for a friend? Having a bachelor party and I know the guy isn't going to go to a verification site. But if I could help him along and arrange a provider I know he'd appreciate it.

on how well the lady knows and trusts YOU.  I have set up a couple things for someone else, but only with a lady who trusts me implicitly.  If you do not already have a good relationship with the lady it could be difficult.

to see anyone without being able to screen him directly, and only having a friend's assurance that he "knew he'd appreciate it." She'd want to be sure first hand that the guy being booked understands what he's getting into and wants to see her.

I hope you're not planning to surprise him with this setup. There may be rare exceptions, but in general, no way.

For ladies that know me well, I have been a referral - in as much as he is not LE. Screening also involves him not being a creep, treats her nicely, etc. You can only vouch so much about that.

Now, for booking for him, that is a little dicey. If you pay her donation, then she might be ok with it. Just be clear that if she shows up, she has earned her fee, regardless of how the groom responds.