I think Starfleet doesn't really care about EMP for whatever reason. Maybe all their electronics are hardened or run on an electromagnetically inert particle instead of electrons (in TNG and DS9 it was neutronic, and Voyager had organics), but when your shields wink out, your guns turn off, and judging from the lights on a lot of armor types I'm guessing our armor has some sort of mini integrity field strengthening it... I imagine your Bat'leth blade disappearing is the least of your concerns.
Thoes walkie talkies are mostlikly more than what they look the Omega gear looks like its for prolonged operations as an infiltration/commando unit. The walkie talkies are mostlikly some form of intersystem trancever with at least twice the range of the simple combage with tons more features to scramble, encript, intercept and decode communications with the same or less power of a starships communications array. Im guesing the Omegas are equivalent to Republic Commandoes of Star Wars durring the Clone Wars era.