Ironically, Ki invisibility would only really work against people who can't sense you, or as a combat technique for melee fighting - you can't dodge/block if you can't see where the fist is. If we want a stealth ability, we should look into Ki Stealth - as in, hiding some/all of your PL from detection. This would obviously also be very useful for Masquerade purposes, and probably be pretty useful in combat if we could hide 100%. If we could either guarantee control over the SSJ2 transformation or put up a temporary ward capable of hiding an SSJ2's PL for a moment and KO whoever hits SSJ2 first as a Spirit Saiyan the instant they break through, then we could break into SSJ2 and just never go higher than SSJ levels without hiding the extra power. (Obviously as the only Spirit Saiyan, we'd have to go last and either control it or get beaten down by 3/4 other SSJ2s.)
We should also get IT up to Exceptional at some point, if only because we want it open to unlocking Elite Talents, which are likely to be extremely useful given the Exile's situation.
EDIT: Actually, considering just how much Kakara loves ki, it might be worth dropping another of the combat actions for a big Research session on doing weird shit with our ki wait that's what New Tricks is.