Don't take them for gospel truth but here is my reply:
1. I have not heard of anyone being banned for too many blogs. But then again setting up one blog may raise suspicions. But then again, having an account per blog for 30blogs is ridiculous. So maybe lump them in groups of fives and put five blogs per account.
2. Not just scrambled, but crap content has been at the top of google before. But you will need to read more on that at the cloaking section and around BHW.
3. Your backlinks will never be of use if those blogs have no follow. Secondly, I am not sure on this, but I have heard that while you do not get penalised if a backlink is from an irrelevant site, it doesn't increase your blog's either. Search around BHW and you will find some tools that will be of use.
