Yeah the only reason to run a bike without brakes is on a velodrome, in the real world on roads and paths having proper brakes is extremely important. If you don't skid your undies don't skid your bike. And if you do skid your undies, try wiping better (or use a bidet trust me bidet is the best)

I wouldn't worry about the chain, KMC makes really high quality stuff and I haven't had any issues or seen any with KMC chains and have installed quite a few single speed chains from them on various customers bikes.

I do like the old screw type Izumi ones personally but I guess I like that sort of connection.