Quick question to confirm a scenario on the jets safe haven tile. If an eJet is on the center blue space, and Drokkatta is on the red space, Can Drok play Arcing Shot to Target the jet by drawing LoS to the empty green space? I don’t believe the blue and green spaces themselves would be adjacent, but would the mobile jet be considered adjacent to the empty green space?

With the current best knowledge, a figure or object on the blue space is adjacent to the green space (and adjacent to a figure or object on the green space). (The blue space is not adjacent to any other space.)

So, I would say yes, if the green space is empty (and in line of sight from the red), Arcing Shot can target it to attack a figure on the blue space.

Alright, great. One follow up. If the green space has another jet, you would then be able to apply blast damage to the jet on the blue space (or grenadier or Drok’s demolish), but Drokkatta’s shrapnel ability to apply damage to figures within 2 spaces would not apply? (as the counting spaces can’t count through blocking terrain).

Note: we're on a non-written territory when talking about abilities other than attacks (and interacts), but this is pretty much how the design team and tech editor(s) see them.

Blast : If the target suffered damage, each figure and object adjacent to the target space suffers damage equal to the blast value. A figure or object on the blue space is adjacent to the green space, so yes.
Shrapnel : You can count spaces into an object or figure on blocking terrain as long the count doesn't go through any blocking space. A figure on the blue space is within 1 space of the green space. So, yes.

The blue space isn't within 1 space of the green space, but the figure is. You cannot count spaces to a space that has blocking terrain, and a space with blocking terrain is not adjacent to any other space, so abilities targeting or referring to a space cannot choose a blocking space (e.g. Pounce, Protector, Sentinel, Flamethrower).

(See also Appendix III - Blocking Terrain Examples from the Consolidated IA Rules. http://www.iki.fi/a1bert/TheConsolidatedImperialAssaultRules.pdf )