if you are running a half link chain all you have to do is take as many links out as needed to have just your chain and no no-railer dont make it too tight but dont make it too loose....
i assure you that it doesnt, these are replaceable dropouts, so the dropouts for the gears would have to be swithched with the singlespeed dropout to work
not entirely true my buddy has a 2006 kona shred with vertical dropouts and runs SS with no railer but he took alot of links out of his chain to do so... he also runs a half like chain
ive had mine for over a year, no sign of breaking, at all, had a kona before that for 2 years, didnt break, frames break man, it happens doesnt mean that there all "shit"
Get a bmx chain it costs alittle more money but it's worth it I have a no-railer on my bike and it broke in like a month and it snaped my chain like 3 times.