I would like to see more customization options for Personal Safes. This may or may not have been suggested before but I doubt all of it has.
An option, maybe an upgrade to a personal safe which allows me to type in names of other players who I am granting access to the safe. (Maybe even a color coded symbol on the front which appears to let you know that you can access that safe.)
The ability to enable items to be placed into or out of the chest inventory via pipes.
A more expensive upgrade which expands the inventory. (I think right now the PS has the capacity of an Iron Chest from the other mod, I'd happily use more expensive resouces to make it larger.)