I'm interested in learning what move to choose when I'm indecisive: which rook to bring into the open file, if i should trade minor pieces, or sacrifice a pawn for position - I do believe I'm the first chess player ever with this problem...

What is the best way to go about getting a local chess mentor?  Are all coaches like 'Searching for Bobby Fischer' intensity, or can I pay for an hour per week one-on-one session?  My only experience is online, and chess.com's local search for coaches is lacking, and a search online brings up children's coaches.

Any suggestions how to seek out a coach to bring me from ~1650 to 1800?

Go to the nearest chess club, and search for a OTB coach. I sure you will find someone rated over 2300 who wants to coach you for about 20$ each lesson.

But you wont get much better by just a weekly lesson, you have to study chess on your own to. I would reccomend How To Reassess your Chess by Jeremy Silman, reading that book will help you with the positional problems your asking for. Check out my review on the book:

http://blog.chess.com/SimonSeirup/book-reivew-how-to-reassess-your-chess-4th-edition