In my opinion, #3 could be an option, if you think it, the Barge is sort of big to die as fast as it sometimes does, a little retouch to its gun allocations and increasing the armor would make it a bit more easy to defend (with escorts, obviously).
Reducing it's cargo space might also be an option. Even reducing it a 50% if the armor is increased enough would still be good.
For some reason, I still feel like Barges could still work like trader FlagShips in some cases, more inRP terms than benefit terms. Acting as a node of storage, smaller than a base, but mobile.