I got a used cassette from this other lbs, it looks like they specify in offroad and "COOL" biking, for free!

So now spacing is not a problem, who needs PVC (well actually i couldn't find any!).

I have a feeling the chain isn't perfectly strait, is that a problem? also how tight should the chain be... at high rpm (pedaling, cascade or what ever) the chain flops... Its also cause it has some really sticky grease (factory).