Imagine the fun you'd have with all the snobby marines (the snobby ones, not the ones who would be smart enough to either shoot it to death or to assault with assault marines, it'd probably survive anything else, not including the HQ choices. You'd have to an idiot to charge terminators, and you probably could out run/jet them)
Those are two very fun ideas, I especially like the ninja'o because it's funny and I hadn't seen it before. I think I might use one or both of those ideas when I rework my tau, although I think a ninja'o would be supremely well equipped to handle the risks of a plasma rifle, so these ideas are likely not to go into the same squad, but I'm a huge fan of missile pods, they usually find a way onto nearly all my suits (it's a deepstriking autocannon with a jet pack! they're amazing!). Whether they're with a fusion blaster hitting the rear of vehicles or wounding infantry on a two, they're always a great backup weapon. I must say I am quite fond of the fire storm from what I've seen of it, it even worked well against a friend's necrons.
I'd probably bet that the ninja'o would work great even if an opponent tried to charge it with assault marines because that'd take one of their best cc units out of its attack on you and weaken a devestator squad in the process. That's sure worth it in my book. And if he deep strikes terminators to your ninja'o, then you just won a major victory and quite likely the game.