I'm wondering if there's some way to increase damage based on how fast I'm going. I already have wall running and I'm wondering if I would be able to get some damage boost for running up the wall then pushing off the ceiling down on to the enemy all while maintaining my momentum as that's kinda needed for wall running.
For a house rule I would add +1d6 for fall damage (more if it is further then 10ft), but you and your enemy would take it. just you on a miss.
There is a feat that does this (I forget the name) but it wont accomplish what the OP wants.
You jump onto someone deliberately and it causes fall damage to them (you both take the same damage I believe). I think it's also performed as a special charge, allowing you to make an attack at the same time. Of course, you are then done for your turn because you've moved and attacked.