I will add some notes about the time and internal loop limits, because they are as important as the hit limits.
Sonya's leg grab needs a hit inbetween uses like Kung Lao's spin, but it's totally impractical. For instance, if you do leg grab, and then try another as they are bouncing, you won't be able to do it, but if you do leg grab, sweep, another leg grab will be possible and register as 3 hits about 54% I think. Also her leg grab has a similar property, of course all uncomboable, but the system is look for hits inbetween.
For Shang's Skulls you need to add 2 hits inbetween or it might be a time limit, similar to Stryker's riot gun.
Mileena's roll also has a weird time and hit limit. It seems that as long as you put a hit inbetween uses, you can instantly do the roll, however, it is possible to get 2 consecutive rolls on Kung Lao without him touching the ground using the time limit. Very tricky.
Kung Lao's hat throw has a time limit, as does Kitana's fan throw which is more obvious.
Reptile's forceballs have respective time limits which do not affect the other one, unlike Jax's missiles.
Sub's iceclone has a huge recharge time, about 5 seconds.
Classic Sub's ground freeze has a pretty big recharge time as well, and cannot be done near the corner.