Yes, there are some bugs when traversing the seas especially during storms. Our longship took some damage in the middle of the ocean, during a calm night. No hostiles were around.

As for anchors, I think something like that would be fine. I'm not a fan of needing to precisely pixel-point move my boat back and forth along the docks, so it can finally stay in place. Having an anchor would at least make the process less tedious.