This came up Sunday, I was wrong on Jink. However there was some confusion I made on a cover ruling. So I also wanted to explain intervening terrain.

On Jink:
The FAQ reads 'Skimmers that are not also Heavy vehicles or are immobilized have the Jink special rule."

So Jink is lost the moment the vehicle becomes immobile, even if you Jinked earlier in the phase the rule is lost after the vehicle is immobilized.

On Cover:

This one is harder to explain but I wanted to demonstrate it's change based on the rule book because it's all too often overlooked. The gist is, shooting through an intervening terrain feature doesn't bestow the save of that feature onto the obscured unit, the save is instead taken at a 5+. Meaning shooting at a unit or model whose line of site is obscured by a ruin, the cover save would not be the same as if the unit or model were contained within the ruin. Which also makes it hilariously possible to get a better save from being obscured by some terrain vs being in it. Like craters.

The rule for cover and it's save is on page: 37. Whether or not you "are in cover behind" or "in" is explained on 108, as is the save for ruin and one's eligibility for the 4+ save. So to get the 4+ ruin save you must be in the ruin, if you are simply 25% obscured by a ruin your save is 5+. Or if you are in a crater your save is a 6+, but if you are somehow obscured by it, you'd have a 5+.

Vehicles are different as their rule states that they receive the benefit based on being 25% obscured.

All that said, it's confusing and I'm a fan of allowing the better save in the spirit of holy crap cover is explained in a convoluted way in the rule book. The whole idea of defining "behind" and "in" is new so if you guys want to talk about house ruling it so that things basically work the way most people play (Basically if you are in or 25% obscured, then take the terrain feature's save.) I'm up for that.