Yep UV knot sense is what I use. You can build it up in such a way so the knot slides easier through the guides.
As for intermediates it seems to depend on the brand. My airflo 40+ lines take a nail knot pretty well and I think that is what Juro uses with good success with a simple nail knot for his leader connection. Sure he will chime in. Also you get some added friction laying the intermediate onto itself when creating a loop instead of the straight nail knot which helps as well.
I have not had great luck with the integral loops. Too bulky and stick in my rod tip. I can make a much smaller one by hand so I usually cut them off.
2 nail knots is probably the safe bet and when one of my singles fail I will join you with the 2 knots. For now I will live dangerously