+6 racial to Climb checks is ok, but I don't think I'd steal more than 1 rank for Climb. I think the Warriors should have a decent Spot check.
CR looks about right.
Tactics: Given the opportunity, isopterite warriors open combat at range by spitting acid in an attempt to blind as many opponents as possible. In melee, they coordinate through their hive mind to flank opponents. Although not aggressive, isopterite warriors will fight to the death in defense of their colony and queen.
Very good, then.
I just saw on wikipedia that termites are closely related to cockroaches. Now that's a horrifying thought --- cockroach people!
I'll leave the description to you, I guess, since I'm not sure how to describe them other than as 12-foot tall termites. Thick-bodied, insect-form humanoids is all that comes to mind.
For flavor: exceedingly colony-oriented, tied together by a strong hive mind. Should we hypothesize that their main enemies are formians?
Rats, it would fit so well with real life! If I ever run an adventure with isopterites, I know what I'm doing.
Anyway, I'm not sure that picture really inspires me much, but maybe it gives you some ideas!
12-foot tall, insect-form humanoids with a long pointy proboscis and droopy antennae?