It likely will. The opening for the phone slot is approximately 3/4″ to 1″ in width. Looking up the specs on the Jitterbug phone, the phone should be able to fit in the case.
Yes, this is a boxy, non-custom-sized item. It should work with pretty much any phone.
Yes. Removable tape is included, so it can be moved/relocated.
Yes, it should fit.
Wallabox will easily stick on your smooth surface- just place the stickers lower than the top corner where it is flat.