I initially thought about doing this thread in the General Forum  section but I think it would be best to get perspective from the DC area hobbyist and provider. I recently called a provider that I see regularly when I am in Florida. I asked her why she no longer tours the DC area anymore. She said that she went UTR because she had a couple clients that were creeping her out.  

I have some genuine friends (4 total, in 4+ years) in this industry, and I approach them with the same respect and openness that I would anyone- I'm cognizant that they deal with delusional, unhinged, and stalkerish guys on a daily basis, so any OTC excursions, Facebook contacts, or LinkedIn connections are initiated by THEM; I respect their limits, and likewise, for the select few providers who I interact with in social networks/circumstances, my experience has been that they respect mine, as well- I'm on the tail end of my hobbying life (bored with the concept), but great people are few and far between, regardless of how I meet them, I treasure and honor those connections- my approach/philosophy may be an anomaly, though, so I understand why many providers keep those two parts of their lives partitioned

Is usually along the same lines as what would creep myself or any other provider out. On a first date or even the third, it is inappropriate to me to ask intimate questions like: "What is your real/first-last name?" "May I come to your home/apartment?" "What would it take for you to be my exclusive friend/girlfriend?" And so on, and so forth... (I'm sure by now you get the point of what would be deemed as an 'inappropriate question.')

a more subtle occurrence?

Reciprocate but do not initiate. I would never email a lady to tell her I'm thinking of her unless she started it.

I totally get it- empathy is one of my strong points

Some clients see providers because they are paying for them to leave, not for sex.  Some don't want a relationship and all the strings and 'crap' that go with it - they want a fantasy.  Some are socially awkward and aren't in a real relationship because they are, to put it bluntly, socially inept.

it's just the email exchange/playful banter leading up to the appointment.

I saw a client well over a year ago and the session was...well he just seemed to need to be subtly rude while being overly curious about my personal life and dismissive of my replies. Special trio of qualities. Over a year later I get a twitter friend request from him saying "hey bet you don't remember me". Though I have never forgotten a client as I have an elephants memory I immediately recalled being left with "What a jerk" feeling after our session. I politely asked how he found me on social media under my real name and he responded that he image searched everything until he got a hit. He also informed me that he had set up an appointment through my agency for the following week.