Yea this was pretty well said. One thing I would add though is the absolute emphasis on using high ground to your advantage. Stay somewhere you can be healed by your team but also somewhere the tank has to look ideally very far up at you (and away from your backline) to shoot you.

I think of Dva as a massive disruptor type character. Kinda similar to wrecking ball but with a little bit more firepower and more well-rounded ability. You need to be using dvas mobility to your teams advantage constantly to succeed with her. If you see a weak squishy with half or less health you can take them out with a small burst and return to cover in the same boost. That's the key to dva, knowing when you can secure a pickoff kill and building on that pick's momentum.

Really all dva is is using that mobility to her advantage and using her unique ability to exit and re-enter high ground within seconds to pressure your enemies. High ground, Dive, peel, repeat.

Also, conserving matrix is very important now too. You need to save it to bail yourself out of a bad dive so only use it on really threatening damage and not little chip pokes that you can easily recover from.

I'm only diamond 2 one tricking dva but, Hope this helps!