I disagree. People that abuse should be banned. People that organise to do things en masse should be banned. If you were to make the system more ‘serious’, you wouldn’t have the option to downvote or upvote your own blog. Regarding the qotw, without downvotes that would not happen. Regarding 5), so what? if I write a 141-character-blog, it gets downvoted. If I do not give the users that downvoted my blog another chance to like my blog, so that I edit it and they can like it, I’d just delete it so it doesn’t receive more dislikes.
If you don’t care enough to read a blog, you don’t care enough for your vote.
But whatever, it’s your site, do whatever you want with it. I couldn’t care less.