@ferro-mortem A dinghy could be fun, although where they'd attach it to the current ships is a tough question. Plus it would negate the whole shark mechanic, which might be something Rare doesn't want... On the other hand, they've featured them in concept art, so I'm sure they've been all over this internally and they'll either appear soon, or have been determined to be detrimental to the game.
A rope to swing... well, that's a whole big level of animation and mechanics that I don't see as necessary. I mean, does anyone really have trouble boarding or being boarded right now? Do we need to make it easier? Plus I'd rather they use all that time and effort for some new foes, new voyages, or mysterious locations, than a swinging rope.
Stealing ships permanently? Taking prisoners? That'd be a really quick way to empty out the player-base. People already complain about foes who chase them down after defeating them... if other players became "prizes" too? yikes.
As to the sloop's cannon supply... I think the ship is just too small for twice as many guns. If you think one gun isn't enough, you know you can actually stand near a cannon and load ammo for a gunner to approximately double their fire rate? Voila! the same iron in the air as if you had 4 guns!
On the matter of the rifle, I guess an unscoped version might be nice to have. Although, I don't see much need for it myself. That rifle doesn't do any more damage than the pistol, so if you need to shoot things at a range longer than the pistol's bullet drop, but don't like looking through a scope, I guess it makes sense. For my part, though, it's like demanding a yellow hat... I suppose someone wants one, but I never will.