When you land Blinding Assault, the enemy loses vision outside a small area for 1.75 seconds.
In this time they have to guess at what you're doing. If you act unpredictably, you can use this against them.
There are several abilities in the game that are "channeled". During the casting of these abilties, if the caster is CCed, the ability is canceled. Thanks to vault, Quinn can very reliably cancel all of them.
This includes most abilities where the user stands still for a while before an effect, like Teleport, Shen's ult, or Miss Fortune's Ult.
These also include some where the user continues moving, like Lucian's Ult.
When you slow push the first 3 waves of the game, you can crash a very big cannon wave into the enemy tower.
If you then recall, you can should have enough gold to buy a cheap item like a doran's blade, cull, longsword, or even tear of the goddess.
This will let you get an early advantage in health, mana, and items. And if you crash a large enough wave you'll reach lane soon enough to not miss many minions.
For the Quinn Cheese, you will start your game off by hiding at the edge of the top bush closest to his tower. Your passive will mark champions only, so wait for the enemy champion to be marked by your passive. When it marks them, Auto-E-Auto, then continue autoing the enemy until they hide under tower. If you do this correctly, you will be in between the enemy wave and the enemy champion. You want to be far enough away from the enemy wave so that you don’t receive minion aggro. This will deny the enemy EXP and CS while the wave slow pushes towards them.
A large number of abilities give basic attacks an "uncancelable windup". This means once the attack starts, they can't be stopped. Except by death or polymorph.
Or vault. If you vault during the wind up animation of any of these attacks, the attack will be canceled and you won't take damage.