Do we have any great theories as to how the humans were able to retrieve McCaughnahey from the black hole? My theory is that once within the black hole, he was theoretically able to transcend time and travel backwards, and that's how he got out. But I have no explanation that doesn't sound stupid.

Also, the Wikipedia entry said that the advanced race that placed the wormhole next to Saturn were humans. But it wasn't made clear to me that they were human. Am I crazy?

My understanding is that they were an advanced race who couldn't communicate with us, so they recruited humans to communicate to other humans for them. It's not remotely clear that the wormhole placement and the ability to put McCaughnahey in a tesseract within the black hole was done by humans.

So basically when he was released from the tesseract they sent him back in time? Because the time it would take Coop to actually cross the horizon everyone would have already died billions of years ago. Interesting twist to think about. I guess the alien/human beings that built the tesseract must of really liked Coop. Since they sent him back in time and across the galaxy to see his daughter before she died. Then gave him enough time and resources to go be with Anne Hathaway :D

I like to wonder something: These human beings that advanced to the 5th dimension, are they from earth or are they the ones Anne Hathaway started on the new planet with Plan B?

It wasn't time travel, it was time dilation that allowed Cooper to see the 100~ year old Murph. Same effect as the dilation on Miller's planet, just to a much more intense degree.

Future humans are able to transcend/travel into the 5th dimension based on the fact that Coop went into a black hole. It is circular. They chose him because he had to and was always going to be chosen. Without him going into the wormhole and reaching the blackhole on the other side, future humans would never be able to open the wormhole without the data he was able to relay back to them (how to control gravity, which in M theory/this film is possibly the only thing that extends across all dimensions).

It isn't not clear that it was humans. They allude to it a few times, and I believe they may say it outright toward the middle of the 3rd act. So basically not Aliens.

It is clearly mentioned that Cooper's crash that he dreams about to start the movie was caused by a gravitational anomaly. Who caused it?

Same thing with the Indian drone and the combines. I think people are so caught up in how the final section of the movie played out in relation to time... what about the first section of the film? The way the film plays out, these gravitational anomalies are all intentional.

The drones and the combines were caused by him manipulating gravity in the house. As far as his crash, I have read theories that it was intentional by the advanced beings so that he would no longer be a pilot. That way he ends up being a farmer instead of being sent on the initial exploration missions.