The proxies with senuke are quite useless as most of them are abused or overused. Whats the difference anyway if you use your ip to social nuke or you use a 'good proxy' the result will be the same if you nuke 10 props in senuke as all come from 1 IP.. or you could submit to 3-4, then use another proxy and so on, would that be a strategy you think??
I also doubt that G could track the the submissions the IP level, this would require the web 2.0 sites to have some agreement with G to reveal private info on their customers, i seriously doubt this is the case, or that G is able to track the content posted from an ip address, its an intriguing thought though..
cheers