I like your guidelines. You don’t badmouth people, you don’t talk about religion and politics. I do think it’s okay to rant, but to keep it uncontroversial or only lightly controversial and try to make it clear you are open to opposing opinions. It helps if its something that you know that most of your audience can relate to, if not all. And keep it unpersonal, as you said. Instead of saying,”I hate my sister because she thinks the novels I write are evil because they are too violent.” (I do not have a sister in real life, by the way) Instead, a blog post can be made about the merits of violence in novels and why violence in novels is sometimes a good thing. That sort of thing. Turn the negative into something positive or informative.

As far as twitter has been concerned, when I go on a positive rant, it has been beneficial to me in connecting with people and getting followers and great connections.