First - Welcome to the forum, good ta have ya here Chrismbello

The problem with the lock up is a lil odd... When the bike locks up - how do you unlock it? Do you have the clutch in or out when this happens? Is it just when you try to start it (if so it may be fine, mine skids a coupla feet when it's cold - gotta just keep pedaling) My first thought would be to double check the tensioner and both the sprocket's alignment, as well as pulling off the chain and checking it for twist and/or binding links...

As for the tank/fuel line/filter/carb connection - I like a build with little room, it's a pain at first when building it but when yer done it looks sweet, often like it's factory. To help you with that tho we'll need a few pics. New members need to make a minimum of three posts before they're allowed to put up links/pics - but that's not much of a chore lol (it's to fend of the evil spam hoards)

Lookin' forward to seein' what you've created