1. Roughly 200baht a day. Can probably go lower for longer rentals, but I'm usually there for just under a week. A small sedan (i.e. Civic) costs roughly 55USD a day.
2. Yeah, not speaking even rudimentary Thai might be a slight issue. Was just there with 2 bros, one speaks very basic Thai and the other English only. Guy with basic Thai was fine but the English-only guy's experience was hit and miss.
4. Well, that's life in uncharted territory. You essentially have 2 options: a. Try your luck, be careful, etc. b. Pay more, i.e. Have the girls/pimp/tuk tuk bring you there. Might end up paying more, might not; YMMV.
Regarding paying more for Tuk tuks, in my experience, the price is the same be it:
1. Riding there yourself (Not really advisable, most girls won't sit pillion, so will have to ride back to hotel and have pimp send them resulting in also having to pay him for transport.)
2. Taking a Tuk Tuk there (some won't sit in a Tuk Tuk since it's exposed and people might see them in it.
3. Ordering straight from the pimp and having him send them strait to your hotel.
4. Not going to a farm but picking up FL at clubs, although again, this will come down to negotiation. Not being able to speak the language might influence this, however.
Hope this helps. I'll be there early Sep, maybe I'll see you there.