Regarding blisters - and this is going to be a bit ming, so brace yourselves.
I've noticed my hands do get sore when using a rower that doesn't have a scrupulously clean handle. When you get a build-up of sweat residue (see - I did warn you) the handle becomes really quite sticky, especially when the sweat off your own hands makes it damp and redissolves all that goo. This stickiness then seems to exaggerate the effect that leads to blisters.
I've taken to applying my OCD levels of cleaning to the handle on my C2, and now the handle seems freer to move around in my hand as I'm rowing, rather than drag and stick to my skin.