Couple of things. It looks like that sprayer is going to sit right under the pots... so when your roots get big they could lay over the holes and plug them up. Can you move the pipe all the way to the side of the bucket and turn it 90 degrees to spray them from the side?
Yes.... you do want air stones FOR SURE!
Regarding the timer... there is some debate about this as leaving it on 24/7 should prevent the nutes from drying up and clogging the sprayer... HOWEVER, in a small reservoir like that 24/7 would also mean the water will get hotter faster from the pump motor always running. A good "mid ground" might be On for 5 minutes Off for 55 minutes.... or something like that.
I don't use aero... but I've read a lot of threads on them so I thought I'd offer info based on what I read. Maybe FilthyFletch or Earl will come along and give you some better advice.... Those guys know their shit when it comes to Aeroponics.
Good luck
