Vintage Peugeot conversion help and tips please

Nice SS conversion pearswick, you have got a really cool set up there! Loving your Beijing track bike too...

In answer to your questions:

1. To remove the chainring from the crank you simply need to undo the five small bolts which hold them together. To then remove the crank from the BB you need a tool called a crank extractor which screws into the side of the crank (where the recessed threaded bit is) and pushes the crank off of the BB.
   
2. I don't think that chainline is as important with single speed; I ran my Peugeot conversion as SS for a while before I went to fixed and although the chain wasn't perfectly straight I had no problems with it. If you do want to try and sort it out though I would suggest using spacers.
   
3. I think that brown grip would look good as it would then go with the brake lever hoods and the decals on the frame. Your call :D
   
4. Sorry, don't know much about headsets, just trying to work out how I am going to remove it from my next frame. Sheldon is probably the place to look though.
   
5. I see what you mean about the back wheel and not quite fitting in with the rest of the colour scheme. I don't know about using white spirits, maybe you are better off to have a search on the forum and find someone who is also having something powder coated and see if you can split the cost with them. If you have a search there is also a really good thread about painting rims.
   
6. Peugeots can be a real pain to track down, I had problems trying to find what mine was for a long time. Between http://cyclespeugeot.com/ and http://www.re-cycle.com/History/Peugeot/Peu_Catalogs.aspx then hopefully you should be able to find what you are looking for.
   
   

Hope that this helps, it would be great to see some finished photos once you are completely done...
Best of luck!