Oil coming out of the turbo compressor outlet is definetely a sign of bad turbo seal.
The line you are referring to with the bottle cap on the end is your recirculating hose to your BOV. I take it you have a VTA bov? I would get rid of that thing and get a stock bpv or a hybrid bov. (my dos pennies)
If you don't want to get a new bov, you can go to a local auto parts store and get a cap for it. They are made of rubber and expand when you tighten them to make for a better seal than that bottle cap.
rollin on 17's now and they're dirty