Nice dude!
On your side flips, you seem to be bending over, kind of like in a front flip. You want to try and keep your upper body straight, bending to your right at the waist. Bending over too far forward will cause you to land too far forward, which in turn makes you fall. Trust me I've done it tons of times. Same goes for bending too far back.
Also, try and get a more powerful punch. I'm not saying flip over the net haha, but just a little more than you are right now.
A few other things, from what I can tell from the video, you seem to be tucking holding onto your calves (yes/no?). You want to either tuck on the back of your thigh or on your shins. You may want to try staying tucked a tad tighter and longer also.
This is just what I could tell from your video, but you'll get it with practice. It took me a while. You might want to try adjusting one of those things I listed one at a time, so you don't have to think about all of it.
I feel like the best way to explain all of this is in a video, so if I get time tomorrow or the next day I'll make one and post it for you, but if you'd rather not wait, these guys are great:
http://www.youtube.com/watch?v=DQ57aoWFltI. Keep up the great work!