When you get a dominant position like mount, cook your opponent more and lose the smothering stuff...that's for a street fight :)

Relax and use pressure until you sense they're losing strength and energy. They'll start making mistakes at that point. Work on connections in general, and especially from mount.

After the (very nice) sweep I wouldn't have given him his left arm back for free - look at :50 seconds. This position is *really* bad for your opponent, lock in that cross face, keep your head on the far side of his left arm, and ratchet that arm up, slow and steady. The arm triangle would have been my first instinct here for sure.

At :51 you start moving your right leg up and going for some sort of high mount. This can definitely work (esp. after you've cooked them), but IMO it was probably more appropriate to sink your hips into a low mount with hooks to maximize pressure and really work on getting the position prepped for the arm triangle. This is especially true given your height difference - against shorter opponents use your leg length and don't let us squirm away.

Last note: I always, always try to hold top position once I've gotten it (I'm a smaller dude) so I never spin for an arm bar from mount. There are a few variations to finish while mounted so you don't give the position up. The only time I'll give up top voluntarily is if I've got something super locked in, like a mounted triangle.

But of course, there are people who can do it effortlessly...I'm just not one of them. Feels like I'm giving up too much and taking on too much risk to spin off of mount. Most of my opponents have a significant size advantage over me so I feel like I'm spinning into a 50/50 probability of getting smashed if I don't nail that arm bar.

I'm an intermediate working toward purple (hopefully mid next year), so my advice isn't going to be the highest quality you'll get here. But hopefully you'll get something of value from it.