If I am running multiple websites I know I should be hosting on different c-class IPs, however is there a danger from an SEO view point that the domains are all registered to me? Can G check who the domain is registered to, I remember reading a patent from G that suggested they were looking into this. Is there a way to hide the domain registration information? I am sure it is just my paranoia playing up, however paranoia and stress are the best slimming tools I know. Thanks for your help.
You can always pay for private registration for your domian. I don't think google cares how many domains you have. They seem to care about the quality of your sites. Don't aggressively interlink to your sites (do it if makes sense) and you should be OK.
I have a number of sites that are in the same niche, so an argument for interlinking can be made as they are all on similar subjects. However I would prefer that they all looked like they were not owned by the same person.
Every registrar should offer a private registration option. In most of the cases you'll have to pay a small annual fee for this
Depend on the domain registrar they'll charge you for making domain name private which will cost approx the domain name registration charges like for example godaddy is charging additional $8.99 per domain name.
You could always pay for a mailbox and forwarding service at UPS yourself. It might end up being cheaper in the long run if you hold several hundred domains and don't want to pay so much for private registration. In fact, if you look up the address in Arizona for "domains by proxy" I believe you will find it's actually a UPS store on Hayden Road. Haha, someone should create "domains MY proxy" and register another box at the same UPS store. Except for the phone number listed in whois, you could almost make every detail the same, including the email addresses.