I've never heard of forcing the AI to walk backwards by moving or jumping towards it. Actually, I'm almost positive that that will never ever work in MK2. It could be possible in MK3 due to the way the AI mimics your movements at times, but in MK2? I don't think so.
On the other hand, jump kick abuse is very possible, and I use that strategy quite a bit. Basically, you need to start your jump from a certain distance from the opponent and time your kick just right, which will force the AI to, in most cases, attempt a projectile, which you'll knock them out of. It won't be that easy to explain the distance and the timing, though, so just experiment until you nail it.
And yeah, you can forget about trying to jump kick Baraka or Kitana; Baraka will pretty much always catch you in his blade fury and Kitana will pretty much always catch you in her fan lift. Against Baraka, however, it's possible to jump toward him from far enough away that his blade fury won't be able to hit you, which leaves him open to any projectile.