Is it possible to hide ownership of a domain, so i won't show up on whois searches for domains I own, even if you know where to look?
Most domain registries require whois information to be publicly available, at least where the domain name is used commercially. The exact rules will depend on the TLD of the domain, and possibly who it was registered with.
Another option is to use on of the "private registration" services that will set themselves up as the owner/contact in whois, and will act as an intemediary for any communications, giving you effective privacy.
It is pretty easy to make up an address. I have personally left the wrong address in my personal domains and just kept one public email address correct.
I get a threatening letter that I must make it accurate, but how would they know, and I can say they really don't care.
It cut down on my junk snail mail for business services.
Yes, it is possible to hide your information on WHOIS. Just get the private registration from your domain registrar. Through this you can hide your personal information. After that check details at a WHOIS service to know whether your registration is private or not. If private registration means your information will be hide on this tool.