It all makes sense. I kinda knew all this from before, but with all the reasons stated, it is the case that reality makes it very difficult, or nigh impossible to do such things such as living on other planets, let alone faster than light travel. It is a shame that this is the case, and finding planets that humans could live on is not so simple at all. The way this universe was made makes it so that it would seem that Earth is, so far, the only planet suitable for us.
Let it be said, reality does suck.
Good news, though, this does apply to any possible species of aliens on other planets. So if there were an alien invasion by aliens from another planet, they would have to adapt to what is on Earth, different gravity, different food, viruses and diseases, etc., and doing so for them may be as difficult as it would be for us on most other planets.