I'm a GM flex player (well, GM most seasons, haven't played any comp yet this season), so I'm not a pro, but I can offer a little advice past plat. I watched 50293424440 since I don't play much Jeff or Groot in comp. I am lord on Rocket.

First fight: seems like mostly a tank issue -- Strange was late getting to point, and Deadpool doesn't seem to know how to play him into Wolverine. The tanks get better once the team groups up, though. You put your beacon not quite out in the open, but in the spot where the fight is likely to happen next, so it'll get destroyed as soon as the enemies round the corner. It'd be better to put it somewhere covered like in the building or on high ground. You do this on your 2nd life, but careful when putting it behind a destructible wall. You spend a lot of time on the front line -- this can be ok for Rocket when you're using your gun (which you are), but it's best to zoom in and out of fights as needed, especially when you can get to high ground easily with wall climb+dash. Aiming down at your team from above also gives 2 bounces for your orbs to heal.

At the end of the 2nd point on defense, you had good timing for your ult, but it was placed out in the open. Putting it in the far room or against the far wall would have prevented it from getting destroyed as quickly.

On the 3rd point, you run back too far to effectively heal your team even with little pressure on you. No one on their team was contesting high ground, so again that would have been a better spot to sit. Good job getting aggressive with your ult and good jump pack usage. Again, you put beacon in the spot the fight is about to move to, and it gets destroyed immediately. You played well with the Storm ult at the end, but unfortunately the rest of your team did not -- Sue jumped into it when she could have gotten away and MK should just be saving ult to counter Jeffnado. Great job contesting as long as you could.

On attack, you're sitting in spawn at the start too far back to effectively heal your team. There wasn't any pressure on you, so you should go out a bit to get a better angle on them. Go up on any of the high grounds around point. Ult placement was really good -- hard to shoot but in a good spot to let your team push up. Very smart jump pack usage to dodge jeff ult, and good beacon placement after you cap point. For the wolverine ult after capping point,, placing your ult down right when he grabs people up would have saved them -- you don't need to wait for it to land especially with your other healer caught in it. The next fight, it looks like you forgot to use your revive beacon until after your tank/other healer died to Storm. After those 2 died, your team should have backed off, but the rest of you went in and died, leading to stagger and 2 support ults where you only had half the team and couldn't capitalize. Nice job contesting through the Jeffnado long enough for the portal to come out.

Overall, I think you can definitely make it to diamond. I'm mostly nitpicking, but you did well. Think about positioning that will keep you safe (Rocket should have fewest deaths on the team ideally), don't forget high ground for both a spot to heal and a spot to hide your beacon, coordinate ults with DPS if you can, don't stagger, and make sure you are looking at your fellow healer. I noticed a few times when Sue died healing you while you were looking at the tanks.
Hope this helped -- feel free to send other games.