I'm still not convinced on chaotic, as they are far too ordered. I'll settle for a "usually neutral", though.
I'm not fond of "trooping gremlin" either. Sorry!
Yes, sounds like the consensus will be true neutral.
Marine gremlins have webbed feet with fins on the backs of their heels. They have a set of secondary gills which enable them to breathe underwater and live in grottos and undersea caverns.
Magic resistance varies according to rank, starting from a basic resistance of 5% for grunts and civilians and increasing by 5% for every two steps in rank up to a maximum of 50% for a Jenrul.
Gremlins are very technology-oriented and are fascinated by any new advances in science.
As mentioned previously, gremlins are fascinated by technology. Upon introduction to a magic-based universe, they immediately set about learning the ways of sorcery and have become quite adept at using magic to confound and confuse the victims of their practical jokes.
Any adult gremlin, regardless of rank, can function as a 5thlevel thief, though generally the only thieving abilities gremlins make use of are moving silently, climbing walls, and picking pockets.
While githyanki are closer to this, they have an alignment of "Usually evil (any)". So if we stick with "usually neutral", that allows for LN, N, CN, NG, and NE. Fair?
I've added an underbar for these variants. Aquatic w/ amphibious?
I think SR 5 + class level might work best here.
Use Magic Device, with the usual "high tech" underbar?
Cleon proposed a +2 racial bonus on Listen, Search, and Spot checks and a +x racial bonus on Climb, Disable Device, and Move Silently checks. I'd add Sleight of Hand to this as well. Perhaps +4 for the second set of skills, including Sleight of Hand? Maybe a racial bonus on UMD checks as well?
I'm good with +2 on all the skills, including Climb. These are already going to be pretty super skill monkeys!