I had questions about the venting when starting my cage install, and came to the conclusion that it's easy to over-think. Rules don't require vent line to be made from stainless fuel line, you could have gone rubber (fuel resistant) hose with it. Clear hose on the vent actually would allow you to see when it's full...
Line goes up, line goes down. The idea is that the fuel doesn't dump when the cell (car?) is upside down or in any other orientation, so the line should snake above/forward/back/below the cell so gravity likely won't dump the entire contents.
The loopy thing you added should help catch fuel, but you should plan on it ejecting some gasoline, anyway. If the pressure somehow is high enough to get the fuel that high in the line, the loop won't do anything to stop it, it will just catch the contents and allow more volume out before spillage (buys you some time), though may end up with gas sitting in it. Make sure it's got a clear path, and no gas could pool at the vent exit.
One thing, your vent is an awful small diameter, and may be a point to upgrade later if it fills slowly. When fueling, the vent line's gotta let air out as fast as the fuel goes in. Our fill's massive inlet/vent allows for 10 second 5-gallon dumps. Used fill plates can be found cheap.
Auto Lemon Union www.facebook.com/autolemonunion
'11 - Point, Sweat, Skank; '12 - Point, Sweat, Vodden, Freeze, '13 Point (+even), Turrible, Vodden, Freeze, '14 Problem, Point, Turrible, Vodden, Freeze, '15 Point, Lemonites, Freeze.