Dang it, looks like I'm done for
For what its worth jump ins aren't bad, but you can't go to the well too many times. I saw a ton of Kung Jin jumpins on the Fatal 8 yesterday. Try to look for a good low starter or low poke and learn to enjoy neutral jumps. You'd be surprised how often a neutral jump wakeup has worked in an NRS game for me.
If you're worried about jump ins might I suggest Jax? He has a move in the air that lets him stop and crash straight down to the ground so he won't have to commit as hard. Plus he does large damage off of small combos, has armor to get in, and has a decent set of neutral tools and corner pressure.
I you aren't confident in your starting MKX ability he's a good place to start to get a feel for stuff. Not too hard, reward is high and he has a bit of everything from grabs, to zoning, to armor, air options and low options.