Jack is my favorite character in the show. Possibly the most intelligent character. Definitely the most sarcastic.
The big reveal about Flint was quite the bombshell.
I'm having a tough time buying that the Spaniards are going to just hang around on the beach long enough for all of the current Nassau action to take place and for Flint to get back there to steal the gold. It would make more sense if they explained that Flint stealing the warship left the beached Spaniards with no way to inform Spain as to their location. Now they have to wait while some of their men trek overland to a port where they can get another ship or send a message to their government. But, I don't think they went into detail as to why the Spaniards are just sitting there guarding their gold.
Ultimately, it seems unlikely that Flint, et all will ever get their hands on all that gold, as the show is all about the pirates/Nassau struggling to gain respect and economic stability.