well that's good then
the impression i got from reading
this made me think it wouldn't be a great option
glad to hear otherwise
His short hop is highest in the game. I will admit that I failed to follow up-throw with Up-Air every single time I played because I kept jumping over my opponent, but you just have to look at the bright side: that just means that that combo can be done at higher percents which is actually much better :D. Also he is able to chase in the air much more than any other champion while still being fast in the air (not slow and floaty like Jiggz or Wario).
As for back air, you can still short hop fast fall it pretty easily. Plus Greninja does 3 kicks, the 2nd kick is done at a 45 degree angle downwards which hit people even if you are still a little too high. You will normally get people with the 2nd and 3rd kick (missing the first kick).
You can also short hop forward air, although you have to start the move upon reaching the peak of your jump and you can short hop neutral air just fine too. In fact sometimes I couldn't even get the neutral air out because of the delay it has (This was just because I wasn't used to the delay, after I got used to it I could do it everytime. Basically you have to perform the Neutral Air slightly before you reach the peak of the short hop, then fast fall and you will perform the move as you reach the ground).