Hello,
you are right, there are a loooot of threads which are helpful regarding your questions.
Anyway, I try to answer most of them in a really short way, as there is no need to go in detail:
Unique IP C Class: With every new shared hoster you normally get a new IP address. If you use SEO hosting, you will have a lot of different C Class IPs. Nevertheless I absolutely prefer completely new IPs, not just C Class. Obviously it can be a huge footprint aswell if every IP stars with 234.123.x.x... If you just want to check the IP of a Domain there are plenty of reverse Domain to IP tools.
Unique Nameservers: Same as for IP C Class: If you use different Shared Hosting services, you will have different nameservers. More difficult if you use SEO Hostings. Bad ones will use the same nameservers again and again. You can mix up the Nameservers with some Cloudflare profiles (make sure to make a new account for every new domain as you will have new nameservers then aswell). To check nameservers, just use Whois tools like who.is or whois.domaintools.com.
SOA records: No need to go more in detail, ignore that.
IP ownership: Same here, just ignore that. If you mix up the shared hosting services, you will have no problem with a footprint here.
Domain registrars: Just use the big ones like Godaddy, Namecheap, Internetbs, Dynadot etc and you are fine. To check the registrar, just use one of the Whois services again. It displays everything you need to know.
Create a unique robots.txt file: Unique robots.txt are maybe a bigger footprint than using the default wordpress ones. 99% of all wordpress sites use the same robots.txt file, so just don't set them up manually. Otherwise, there are many plugins to edit the robots.txt or you can just put in your unique one via FTP in the root directionary of your website.
Block bots: You can do this with .htaccess but its really difficult to filter every bot and moreover it can be a huge footprint if the big G would simulate different bots and see that all the websites are 403 denied. I used to block all bots via .htaccess a long time ago and it worked for about 2 years but suddenly majestic changed some names and had completely access to my websites. After that, all my PBN websites were revealed by majestic and some weeks later also from Semrush and Ahrefs. So, decide yourself: block all bots with .htaccess or just ignore this case as I do now.
Create random Whois data: It was more relevant to do this before GDPR. Now the whois data is protected in many cases so it is not necessary anymore to create fake whois data. Anyway, if you want to do this, you can to this very easily with Namecheap, Dynadot, Internetbs, Namesilo and so on. You can set up individually whois data for every registered domain. Make sure that the fake info has a valid address. You can use G Maps for that and search for any address in the world. But as said, its not as relevant as it was before.
The most important thing now is: Create PBN which dont look like PBN. Buy high quality content, design individual logos, make it relevant to the old topic (in any way) and create content which fits to the expired domain.
