Does anyone actually understand how to explain?

This is exactly how I feel. I used to be somewhat interested in sports video games, but it finally dawned on me one day that the only way to really be good at sports games is to put in a long process of time and commitment to get better at it (or just play on the easiest level, which is way too easy to be fun), and I didn’t see the value in making that commitment. But I like martial arts and hand-to-hand combat and Marvel characters better than sports, so this seemed like a hobby more along my line. But it is just a hobby; I think there’s precious little chance that I’d ever be able to make a serious go of it in any professional capacity, so the only real reward we amateurs ever get is the feeling of success or mastery of a skill. And that is pretty hard to get when you’re just starting in this genre.

Umm…
You can hit d/f again…

F, D/F, D, D/F+P = will execute a SRK in every Street Fighter Game

That’s all I’m contributing to this thread.

That is a point of frustration for many Marvel 3 players, since Capcom decided to make replays a feature exclusive to the Vita version. Without taking your own video of your gameplay, whether with some kind of capture device or the ol’ fashioned way (with a camera pointing at your TV screen), it can be difficult to judge where you went wrong in the heat of the fight.
The thing about Marvel 3 that makes it difficult for newer players to grasp, especially compared to something like SF4, is the pace at which things happen. Characters can apply mix-ups and get past your guard in the blink of an eye, one mistake can lead to the death of your character, and the eventual deaths of your other two characters upon their entry if you fail to guard against the incoming mix-up.

At this point in the game, people want you to practice your execution because that’s the first step to becoming proficient. If you can’t make your character do what you want, then you can’t play.

Marvel 3 is a difficult game for beginners to grasp because there’s so many varied situations in it that may not have intuitive ways of escaping, and that if you fail your character will die and your next character will have to successfully escape a mix up. Also, it is a game that requires combos, since it is so unforgiving, you yourself must be just as unforgiving of your opponent’s mistakes.

If you can, try to put up some footage of your gameplay onto YouTube. Even if it’s some ghetto shakey-cam stuff, it’ll still show what you need to iron out. From your posts, it’s probably every part of your skillset that needs tooling, but a video can help people point out specific things to work on.

You’re over-thinking it. A cancel combo is when you combo 2 or more moves together by canceling the initial move(s). The LMHS combo (or if you have a PS3 and the button layout is set to default, Square, Triangle, Circle, X) is an example of a combo that utilizes canceling, since each subsequent attack cancels the animation of the last. For UMvC3 in general, all you have to do in order to cancel a move is to do the next move in the sequence. If a Ryu combo requires you to do a Hurricane Kick (quarter-circle back+attack button) and cancel it into a Shinkuu Hadouken (quarter-circle forward + 2 attack buttons), then you simply hit them with the Hurricane Kick, and while he’s still doing the Hurricane Kick, input the Shinkuu Hadouken. Ryu will immediately stop doing the first move and go into the second.

Fighting games are hard. There is no magic bullet, rarely is there any instant feeling of success or satisfaction. Yeah, a bit of a downer. Probably the best thing you could do is find a friend/a coach who does know how to play fighting games and have them help you along. You will probably progress faster and feel/see the progress more easily too.

The very basic basic basic umc3 guides on YouTube may be helpful to you(not good for anything other getting your toes wet.)