thetray

I'm in the process of converting an old steel Motobecane road bike to a single speed. I bought a chain tensioner (Forte brand from Performance) and got to work. Got the tensioner on ok, but when I went to work on the cranks (SR Suntour, square-taper BB) I noticed that the rings are RIVETED together. SO..I now need to get a new crankset for my project. My questions are as follows...

1. Will a track crankset work?
2. What is the difference between 3/32 and 1/8? Which is most common?
3. Is the White Industries ENO rear hub (flip-flop) hub worth the time/money investment if I'm brand new to SS?
4. When installed, should the chain tensioner hang straight down like a DR or be more flush to the rear triangle? (The Forte tensioner didn't come with any picture instructions)

Thanks in advance for any advice.