I figured I had probably taken it to an extreme

I just want my furbaby (when I get one) to be happy but also trained.
I think the dog door will be nice too! Once she gets a handle on it and gets older, we can just let her take herself out.
How should the play pen be? I've heard that if its too big they'll pee and poop AND sleep in it? But I also want her to be able enjoy it too....