I dont think it'd cause confusion so long as they make sure people know about it. Obviously fire-support would be arse holes about it but most others should take to it well i'd have thought, especially those who aren't as big as z1, fs, wa, lwa etc
"hey mate, that gun you wanted that is always out of stock! *link* -damn! only ukara". just a though. can imagine customs being a bit cranky about it for a while as well.
Yes but retailers are after to sell guns. They would have no reason to only allow ukara, (except fire-support who've never accepted anything else). Assuming this became popular retailers would be fools not to accept it as a defence, they could potentially lose sales by being picky about what to accept.
they could also lose their businesses, get fined or face jail time if they aren't picky. I can't imagine for a minute any retailer doesn't want to sell to someone, rather that they legally can't (or cannot prove that the they legally can)