Just to be clear, no the props are not designed to be "pilotable", and at this point they cannot be destroyed. However, an awesome ship is an awesome ship! There is still a huge amount of naval stuff you can do with this, so I wouldn't worry! (Two ships in the sea, ladders to get up with plenty of longboats, siege gamemode, one is the attackers spawn and one is the defenders. And already we have an intense and fun game).
Mount & Blade Warband's engine really does pretty much stop anything naval in-game unfortunately.