I've gotta disagree with a few of your points.
Most people cannot comprehend interstellar scale - just how vast, and mostly empty, the observable universe is. And how can you comprehend technologies that, by current scientific thinking, are impossible? It's one thing to say "Sure, I understand it's four and a half years to the next solar system if you go at light speed", but do people actually realise how fast that really is, what's involved in almost getting to that speed, and how far away that really is?
Considering alternate realities, there's always the many-worlds interpretation of quantum theory, and that's not some crackpot, loopy theory, it's science.
As for your first point, how can we know the motives or thinking of an alien race? Their way of thinking could be totally, well, alien, and incomprehensible to us, and their actions could seem pointless or otherwise messed-up.
Not having a go at you personally, just a bit of debate
The truth is out there Anyone else seen the new movie? No aliens