Use a store that belongs to a deed I own ? / Use my own store ?

Stores that are on deeds that you have authentication on are in "management" mode for you, e.g. not usable for selling to them, but for configuring them.

I don't know out of my head if this will work, but you could try to have the deed with the stores on them owned by a title that you are a manager of, but not a holder. If it does work, you could add yourself to holder everytime you need to change something on the deed / store and then remove yourself again.