Re: Chain and alignment questions...
You can use a chain breaker or even a bench grinder to remove links. I used a Parks bicycle breaker with much success, just don't try to use the bell walmart breaker, it will break instanly.
I have built several bikes, and this latest one I just set up as normal, only to find that the sprocket needs to be flipped....first time for everything I guess, but not a big deal. Chain alignment is very important, so do what it takes to get it straight.
You may find on some bikes, you will have to put the tensioner in a vise and twist it slightly so it will run in line with the chain. The tensioner bracket is a relatively soft metal, and a pipe wrench or big pliers and a vise will do it.
Don't try to get the chain tight- 3/4" of freeplay is good.