Lets say I found a 1000 page Pr 2 blog with comments enabled. How many posts should I make for my website on there considering that all the backlinks will be coming from the same IP? They are also nofollow. Does that make a difference on how many I should get from that source.
Use scrapebox to check their PR and spam those with PR only. Do not spam the entire site because that might piss the owner off. Having a lot of backlinks from the same domain won't give you a significant advantage anyway.
Ideally 1-3 backlinks from each domain would be sufficient, however, if your competitor is doing the same thing then you want to outrank them. Unique IP's = Victory But if your competitor is doing similar things as you are, and they have 4-7 backlinks instead of 1-3 on the same domains, then they'll outrank you.
It is not like having too many is going to hurt you but the more you get the less each of them is worth so use your time accordingly.