1) A properly done conversion (no changes to the frame such as cutting or dremeling off parts of that which make up a road frame) can be a good FG bike. It's esp nice to see a classic steel frame from the 70's being ridden instead of gathering dust. Even a lesser quality frame can make a good candidate for a FG conversion as long as it has horizontal drop outs (so as to get the correct chain tension).

Many of the old school road frames make a better FG than the cheap entry level FG specific frame (such as those from BD) because the tubing and workmanship is of a higher quality.

2) As for the use of brakes, that means the rider values his/her own life and that of others (such as pedestrians). As has been already posted, with a brake you can run a higher gear and thus go faster. No one who values their knees runs a 75-85" gear and tries to backpedal. At the track they tell all the noobs to NEVER backpedal so the only riders doing this are are the urban chic.