Let's just stick with "pack" like the original.
I vote "yes" on Reptilian subtype. Since they're humanoids, "Tortle" should be a subtype as well, methinks.
While in principle I agree with you on the Tortle subtype, the Dragon mag 3E version of the Tortle doesn't have a "Tortle" subtype, which suggests we should omit it.
I'd like to leave it Reptilian, though.
Since we've essentially scrapped that version, though, I see no reason not to add the subtype.
Are these ready for the tactics and flavor already?
I'm not the LA expert, but that seems ok.
"Usually LE" makes sense for the alignment given the standard tortle is LN-ish. The text of the original monster could be NE, but I don't think it matters much.
Tactics: Snappers are ill-tempered and territorial, apt to fire their crossbows at the least provocation. In close quarters, they attack viciously with claws and bite, and they aren't above attacking opponents who've become tangled in their nets.