Don't get hit. 
If he tries hard to hit you he'll be missing out on CS, if he doesn't he'll push the lane. You'll still get hit a few times, but you should manage that easily with consumables and/or regen items.
Stick/Wand is useless, Tidebringer doesn't add charges to it.
Not sure about that. His range on the splash is pretty long, almost to the xp limit. Most players I play against end up having to run the fuck away because I keep them on 25% health. Torrent is just stupid if players don't see it but so many don't it's unbelievable. The amount of easy kills I get just from putting torrent on someone I've bled with tidebringer.
His ship is lethal though. Best to save it for half way through a team fight when there's plenty of confusion and low health players, then BAM, high damage and stun. Most don't notice it despite the enormous ship/noise that it makes.
Basically Kunkka is great for taking advantage of dumb unaware players, of which there are plenty in Dota. And like Rufio said, combined with another stun of some sort he is lethal as it gives you time to line up torrent and ship.
Favourite tactic though is standard cast x marks the spot, torrent and then fuck them up with some fast sword slashes. Against squishy characters it works a charm.
