As has been said, the more desperate you are, the easier it is to exploit you. New people attract those hopeful of finding someone to exploit like flies.
How much do you need the larger sums? Both those 'bookings' are making me concerned.
Domming you in a public toilet - if this actually happens and it doesn't end up with you both breaking the law, I will be amazed. Do you know what your boundaries are? How are you going to stay safe? If you end up covered in urine and faeces, what are you going to do about getting home?
Virginity - I'd be surprised if you couldn't get more for it. (More than once, if you're a good actress.) The fact that he's offering this to more than one person suggests to me that there's something fishy going on. What happens if you say that you've had other offers and you need a deposit - say ?50 - from him if he wants to secure his place? (Do a search here to find good ways to get this - PayPal isn't one.)
The main payments absolutely have to be in cash. If you haven't already done so, read the
main SAAFE site.