DynamicUno

No, if a provider is not currently seeking business, reactivating his ad could be a significant problem for him. The ad may need to be revised before he could accept new inquiries.  If he's returning to active availability, he should be in control of his ad.
I can see the utility of letting clients donate to active providers for their RM ads, but inactive ads should be ineligible.

I would guess it covers things outside of the normal range of bumping uglies, but I doubt there's any consistent meaning.  You'd have to ask the individual guys what they consider a special service.

PDA should be negotiable, especially for longer engagements like overnights since public activities are usually involved.  The problem is it's not often discussed in advance and depends on each person's comfort level in the moment.  In this case, if the escort was uncomfortable holding hands in a theater, he is very discreet and should probably let clients know before an long engagement.
It should always be OK for either party to say "let's keep it more discreet for now" if they're uncomfortable.
For the escort's side, I'd say follow the client's lead and only initiate PDA consistent with what the client has done already.  I'm not as sure what is best in the client's case, however.
The client's reaction, in this case, seems excessive. I wonder if there was more to this interaction that lead to the client dumping the escort (something that came across as disgust or rejection?), or a verbal argument?
 

It sounds like you found someone who was extremely new or had some other issues going on to be that paranoid.  Most massage or escort providers you would find on rentmen or rentmasseur know how to navigate encounters with prospective clients.
If you are looking to hire for only a massage and are trying to stay strictly "within the confines of the law",  consider using rentmasseur and requesting theraputic services or getting a massage in your hotel spa.  Las Vegas is not in one of the counties with legal brothels, and hiring for sex in LV does violate the statutes.  
That said, providers in Las Vegas advertise openly on Rentmen and guys hire them all the time for all services without issues.  There's very little risk of attracting LE attention as long as you're reasonably discreet, especially if you hire a well reviewed provider.  The resorts are not concerned about providers visiting guests, they are more concerned guests getting solicited on property or detecting exploitation.
A number of members here hire in LV and can answer questions.