was wondering if there is any speacial reason i should save the nuka cola quantum like in fallout 3, does it have any speacial use in fallout 4, or is it just a drink

I've been wondering the same. I've naturally being hoarding everything that was mission-important in Fallout 3 just in case - must have 50 Quantums stashed in a cupboard by this point!

if I stash things in a place other then the work benches will it stay there permanently or do I loose it after while

as far as I can see, its just for consumption.

You can make bombs with them.

I've got my own little pad set up on the top (fourth) floor of my settlement at the Drive-In. I have different containers for different types of items, I have some things loose on shelves and my magazines in racks... Nothing, to my knowledge, has ever gone missing. That said, I have very purposely never put a bed up there, so there's no reason for settlers to wander up those two extra flights of stairs!

I never sold the quantum in fo3, I always hoarded them and used them to decorate rooms and shelves

I don't use them, but they seem to be more beneficial now to drink in this game than in FO3 and NV.

Of course, there is more than just Reguar and Quantum out there...so I'm collecting a bunch.

I am hoarding mine until I can make Nukagrenades.

As with past games, I'm just collecting them all. Regular, Quantum, Cherry etc.

I have a container specifically for Nukas.