Hehe... I was smiling when I saw your abuse of u/f+3. (J.A.N. :P) But it's GOOD! I saw that this Marduk got really nervous.
To be honest, he exploited your massive attack. Marduk is great in getting the hell out of his opponent's way. The only thing you could do is marking an attack. And abuse QCF+1 on Marduks BTW, DGF is better when escaping tackle. Yoshi enters it faster.
As for tackle: remember that you actually have to input the correct button and HOLD it to parry a punch. You nearly escaped the punch once, but you released button. It's good to mash 1 and 2 continuously, and watch what Marduk is doing. It also helps you to focus. Then, press 1,2 or 1+2 just before the punch reaches Yoshi. It can be done, my efficiency sometimes reaches 90%.
Your opponent learned fast and so you lost quite a lot of damage on unsuccessful u/f+4, 1+4 bread-and-butter trick. Try to fight in "real time" And where did you lose SS+1?
But You're better than me in correct punishing d+4 and ducking his nasty 2,1. GOOD!