Given that the intent of the ability seems to be pretty clear (it is spelled out in the last line, under "Special"), I can't imagine any GM would allow a non-Thri Kreen-type to take that feat. That isn't a "small" requirement by any stretch. The ability/feat exists to fill the gap for characters with more than two hands, if you have only two, then their is already an ability for you: Two-Weapon Fighting. Of course, we're talking about a monk here, so both of those feats are useless to them anyway. When flurrying, a monk's attacks are hard-set. You can use weapons as part of an attack (usually only monk-weapons, unless you have a feat), but they're not a separate attack, they're just part of the flurry. I can have two characters with the same exact stats and they'd be nothing alike. Building a good, unique character isn't about the build, but about the character him/herself.