Re: Drive train
One good way to double check alignment is to spin the wheel in BOTH directions. If it spins free without any chain popping or noise even backwards, it is good.
I ALWAYS have to add a twist to the stock tensioner bracket to get it properly alugned with the chain. I use a huge crescent to carefully twist it.
I agree with 2door about not being a fan of springs, but if you DO use one, it must still be straight.
If more is better, then too much is just enough.
If you can't afford it, build it yourself.