Having Piscatoris as a functioning place is something I'd be all for.
It could just be another alternative location to catherby or mudskipper point, that would already be enough. If rocktails are going to be added they should be in living rock caverns. If fury sharks are made fishable they should be fished in the wilderness.
In order to make it unique we could add a boss these. Now I know what you're thinking a boss sounds absolutely nuts as far as skilling goes but I think it might fit quite nicely. The sea troll queen would have a chance to spawn every 30 minutes, this chance is increased the more people fish at the spot. She will atttack anyone that is trying to fish there with magic attacks. For those that don't wish to fight the sea troll queen this is the time to cook your fish. For those looking for some extra loot, this is the time to grab your range/mage gear and kill the boss. She would drop various fishing related items, noted amounts of raw or cooked food, fury sharks, noted caskets, snape grass. Anchor could also be moved to it. It could also drop the item to imbue rings with which you suggested earlier.
^This thing