These are great suggestions!

And I've already implemented them in my trade settings. Thank you for creating this.
But...I do have to comment about this, I hope you don't mind?
Starstreak wrote:....Okay, what? It doesn't matter if the pet is re-released or original. It's still the same pet!
It kind of annoys me when people put rules like this. It also annoys me to encounter people trying to get a complete collection. Or those collecting pets based on rarity. You should collect a pet because you like it, not because you want a "complete collection" or a "UR". It's impossible to get a complete collection anyways unless you joined in 08 or unless you cheat which is bound to get you banned. Collect pets based on what you like, not on release date or rarity or trying to get a complete collection. Trust me, collecting anything except the pets you actually like is just going to make you stressed out. And this is a game! You aren't supposed to be stressed out! Chickensmoothie is supposed to be for *fun*
No correction for the above rule because my recommendation is not to have it at all. Not only is it pointless but it will also chase traders away.
I have a large collection myself, it's 91% complete, literally. I'm only short 94 pets currently. I'd like to have a complete collection, but what's the harm in that?
I agree with you on only collecting what you like...but what's wrong with liking all of them?

I adore CS, and I adore virtually all of the pets that have come out. Some of them have fallen into my hands from random trades that I wouldn't have normally gone after...yet. But there's nothing wrong with wanting to have a collection.
And to state that you can only get it by cheating if you haven't been around since 2008? That's harsh.

A lot of people trade with CWP's, and trade with C$, to get things they normally couldn't trade for.

That, and some people have help from those who were here in 2008.
Not meaning to nitpick, or even be close to being mean. Just thought those were unfair statements.

Anyways, just my two cents, lol.
~Flitter