ah ye old walls of text. Last year in phisics we talked a little bit about Carl Sagan and the SETI proyect. We saw a couple of vids and stuff, it was quite interesting.

It might sound weird but if there is a more advanced race out there I think tht thei intelligence level would be close to us. The diference would remain on what they know, not their intelligence, we have abstract toughts which make us more intelligent that the rest of the species in this planet. However, if there was a race that had a similar intelligence to our in an other planet, but way less advanced, I could almost bet that we would try to communicate to them. And I believe that if there is a more advance race than us they would try to communicate with us, just for the lols you know. It would be a unique experience to see how undeveloped smart creatures behave and think. I believe that they would not miss such an oportunity, it would be almost as if they were traveling in time.
The zoo theory however sounds kinda possible, it would be a nice way to learn from us. And yeah there is no way to know if its true or not, for now at least.

The most probable thing in my opinion is that travelling to earth must take shit ton of time and if they are indeed coming it would take them lost of years. Since the space is so big and the distances are really massive, taking into account that the fastest you can travel is the speed of the light, and that so as to travel that fast you need to become energy, I guess they wouldnt even bother to come or since we are so far and the light actually takes quite some time to travel, what they see is the old earth before life even existed so yeah, kinda sad?