So does anyone know how I could get my adoptables to be displayed on the forum profile or have a different type of profile on the main site?

And can someone show me how to rewrite the levelup page there?

Well... This is gonna be quite difficult since you have to be familiar and comfortable with MyBB's coding style. You will need to modify the core script of Mybb user profile, which will require at least intermediate programming skills to complete since they use OOP(so yeah you have to not only understand OOP, but also code in OOP). I can help you with this in summer if I am not too busy working on the new version.

Another risk you have to consider is that you will not be able to upgrade the forum with their upgraders. Id say be extraordinarily careful if you take this path, since manually upgrading forum is beyond what I can help with.

Rewriting the levelup.php is gonna be a much easier task though. What do you want the page to look like?

I can leave that for now perhaps... I guess I can fiddle with stuff and see how I can do it otherwise.

I'd like it to add something like this to both the levelup and already clicked display;

Information:
Owned by: [owner]
This rat has [x] clicks and is [x] stage (level).
This rat is also [trade status].

That's about it, I believe.