It's great that you haven't had any dog trouble. Dogs here are not so well behaved, unfortunately.
With the eye, I noticed it mainly in the one that you are holding on the magazine cover. What may be a bit of dried seepage coming out of the front (tear duct). But I'm only looking at pictures - you're able to see them up close every day so you will of course be a far better judge of their eye condition!
A few of my ducks are not interested in swimming either. They just like dunking their heads
That's all they really need for eye and bill health though.
When you go on the bus and tube with them are you taking them somewhere in particular or are you all just going for an outing together? Do many people come up and start a conversation about them? The ducks are obviously pretty relaxed about it all. They don't even startle when the train arrives on the platform. I did think it was funny though that when you are sitting at the tube station and someone stops to speak to you the duck on your lap tells them to 'nick off' with his head movements. Made me laugh