Just my 2 cents, I like the name SpaceShift Editor, I do not like any of the names in the poll.
If you must change the name then I have suggestions:
The JME3 Fantagulator
XED for JME3 - pronounced ZED, referred to as the XED Editor or just XED - from: gfX EDitor - or even as Xtened(or Xtensible) EDitor - you can even create XED for Unity and XED for Unreal 4 depending on how much time u have (i.e. it is just branding), it doesn’t even matter where the name comes from.
NaN Editor for JME3 - Got the name from Not a Nazi Editor (poking fun at the reason you want to change in the first place), we gotta be able to have fun eh? Also NaN is programming related. Could even be NNaN Editor (NNaN is not a Nazi, good old Nan), it’s a recursive acronym like GNU, you might be locked in to using an old woman as the logo though.
I like XED Editor (I don’t think it matters that it is GFX Editor Editor), however there is a Xed Text Editor out there but who cares about that eh?