Is it rude to bite randomly? I am really lost on the biting thing. I see some people have the Bite link but I do not know if I am supposed to just bite random people or not.

if they have the bite link and you can see it I think this means you have the strain that they want or that they allowed 'random' as a choice when they signed up.

Back before VIP when people wanted certain strains they'd hang out in specific threads, but in the end this stopped nobody from biting them and sometimes they'd get a different strain than what they wanted.

Oh that makes sense, thank you very much :)