To the second part of your question, trading unfairly is not in any way against the rules, as many players don't know values very well or just don't care if something's fair or not (and thus there is also nothing wrong with doing the paperclip challenge. It's just a matter of finding someone who's willing to go along with it.)
You're only breaking the rules if you claim that the trade is fair or that the pets are worth more/less than they are when that's clearly not true -- then it would be considered a scam and you'd likely get in trouble.
You just want to be careful, again, especially with people on the same IP as you, that it doesn't look like one account is only there to benefit the other. So you'll want to keep trades with family/friends more or less even.
If you ever want to send a big gift / very unfair trade to a friend or family member, it's best to be safe and send a
help ticket to the admins for permission before you make the trade so they can check if everything looks okay.