I want to disconnect the tube in the Red Oval (from the throttle body to the charcoal canister) but it's stuck pretty good and I can't locate what exactly this is. I assume it terminates on a connector similar to those in the Green Oval.

What is it and is it safe enough (after moving the clamp) to just put the pliers on it and twist hard until it breaks free?

 

I ripped mine out with no issues. To my knowledge it just vents to the charcoal can for filtration, I would replace it with a stock rubber one though.

 

after the clamp is removed; if at all possible, try to slip a pick up under the end of the hose and squirt in some silicone spray or WD-40. when trying to get that hose off use regular pliers and twist and pull.
LOL @ original fuel filter