There are no more arguments to say since everything has already been said.
And like stated earlier, the Zoro thing and with Usopp are two entirely different situations lol. Not sure why you keep mentioning that.
Zoro never left the crew, so why is this comparable with a member who picked a fight with his captain, talked a bunch of shit and actually left the crew.
The way I see it is simple. Once Usopp left the crew there was no more "Vice-Captain" so to say that Usopp is Vice-Captain, where is the proof that Luffy gave back Usopp his "Vice-captain" status?