Medved,
Before you commit to some major and expensive changes why don't you sail it for a season or two so you can more accurately determine want you really need or want. C34s are pretty nice sailors right out of the box, you never know you might be happy with the way it's currently set up, the guy you're buying it from was.
As far as the Genoa goes, I've got a 155 full cut deck sweeper that I got when I was racing, I still have it and use, and yes you have to do a little more peeking around the sail but it's not a big deal. If you think it's a problem you can always have the sail cut to provide better leeward visibility, however there will be a cost in performance.