may not need the brake line, the large loop at the mastercylinder end might be enough.
A common addon to aftermarket swingarms is to add the banshee chain guide. There $12 or so and hang in front of the rear sprocket.
Might pull the rear shock and check the line thru the travel of the swingarm, can also check the chain for tension at the bottom of travel
I honestly couldn't say how long any of my chains are. Whenever I buy a chain I usually get 110 or 120 links (depending on what swingarm I'm using) and cut them to size. This is because #1 no comprehensive and reliable list exists detailing the length of 520 chain needed for all swingarm lengths for a raptor, and #2 because the use of different sprockets would render such a list useless.
I should be able to give you a ballpark within a few links but I can't recall and I have no idea which chain on my wall fits what until I try them out.
i got a +4 on mine and bought a 120 ling chain and cut it to length, the stock brake line is fine and never changed it. but the stock shock sucks now, i added all the preload on the spring i could and when i sit on it the swingarm is almost flat( i weight 250) so invest in getting the rear shock revalved.
I ran the stocker on a +2 for a year or so and it held up pretty well. I just had to tweak the settings to compensate for the increased leverage. I wasn't jumping though, just a lot of big whoops uphill.