Slot sucks?

Yeah Slot is pretty basic I hear ya, and becomes fairly weak for the WoR.

Meteostrike is her Desperation Attack actually, her other main slot attack is Surge Cutter I think it's called.
Besides the ones you mentioned, slot can always have a chance of scoring a random esper attack with the 3 BAR and if the 3 Dragons line up it's a summon Bahamut, but those are much rarer but can be timed out, much easier with pause abuse...

I'd say Tifa and her Slots are really strong for most of the WoB, but yes played out and not so great when the WoR comes along.
Her Bunny one is like a free remedy for the party it can at least be somewhat useful instead of just something that says MISS! and gives ya nothing at all lol.

The slots are auto-rigged still, I had that removed but it was just a big hassle for me to time them up and it was pretty much Bunny every time then, so I changed it back. I think a lot of the outcome is due to the first slot you get, that with some randomness determines the outcome of final slot combination, although sometimes it does seem like timing is used as well, especially for the 3 BAR random esper attack one.

So yeah, Slots is still the same as Setzer's Slots in terms of the code for the rigging and percentages or w/e, I just changed the attacks.