Hi Dave, You have to do a 1/4 turn of the pedals before the throttle will activate I believe. You can't use the throttle to take of from a stand still if this is what you are after. The only way around it would be to activate the walk mode which takes about 3 seconds to activate.
It should definitely be possible to ride the Level on throttle only according to Aventon's site: "Throttle speeds of 20 mph mean that, even without pedaling, you can easily keep up with the traffic around you."
I don't know about your bike, but in the advanced setting on my Himiway I can make the throttle work from zero speed without having to pedal at all. It can be set like yours that requires about ¼ turn of crank before the throttle with work.
Personally I really like the throttle working from zero in tight spaces, PAS always kicks in too much for tight spaces in my opinion even when set to PAS level 1 20% motor power. This is only one of the reason I like the Himiway bikes over other ebikes in that price range.