Well,the idea sounds nice, but I wouldnt go that far with it. Those who tell,that this isnt Diabolo or WOW and its based on original fallout,well the problem is, that FAllout was propably never meant to be massive online game, so little changes would be appreciated,especially when we cant have all the weapons and armors (power armors and things like this,which are forbiden) which were in the original single player game.
On the other side, I would prefer making footlockers more common,Bps less hard to find,more armors,fix crafting drugs and obtianing HQ material etc. I mean, lets just fix what is neccessary and then we can make ideas about special upgrades...
We could also connect this idea with joining to BoS or Enclave, cause the idea of upgrading armors if we take it the way like *whopa wasteland style*, these kind of things should be able to do high qualified mechanic with technologies for improving armors and weapons,and these people could be find only in the factions like BoS or Enclave...at least,we would have a chance to make more quests and options to them,and pros which would give players a motivation for joining to them..
For example:
Enclaves - improving high tech armors,some weapons (like kevlar armors and for example big guns)
BoS - ability to upgrade BOS kevlar armor and some other + small guns..