Yes, Feeder do have access to dizzy donut stuff even if their feeder level is low. Or better say, have access before the Dizzy Donut Branch opens in your City.
Lore technically you can explain it with Dizzy Donut already existing beforehand, think of the undergound lab. And the feeder, sometimes, already have an immobile character in their house, when you visit them.
So you could argue, that they have some "connections" to get their hands on Dizzy stuff.
And for fixing the addiction, before the branch opens...well there is nothing, but at least you are standing before closed doors, if you don't want to gain fast.
I use metric so I cannot comment on the feet problem.