How to keep competitors away and keep search engines happy

The more one way organic incoming links your website has - the higher it ranks in google and other search engnies. Problem 1: If you own 2 or more domains and link from domain1.com to domain2.com - this absolutely has no effect on ranking of domain2.com. Search engines knows that you own both domains soit will not grant more ranking "juice" to domain2.com. Problem 2: If you into affiliate marketing - you do not want your competition to "spy" on your business, duplicate it and steal your profits. You don't want others to know all your websites, you want to keep your businesses "under the radar" as much as possible. Here are suggestions to solve these problems:

1. Register domains under "pen" name.
2. Use P.O.Box that only takes mail from that pen name.
3. Get a dedicated server and have every domain, or group of domains, under their own IP addresses.
4. Do not host your websites on a single IP address. It is easy to list all websites under single IP address by either using domaintools for a small fee, or running query on live.com, such as: ip:123.4.56.78
5. It is not always a good idea to have "proxy" or "private" registration. Search engines suspicious of that and you may have problems missing important messages regarding your domains. See #1 + #2.