1. If aliens were invading, what would you do, hide or wait by your TV?
Neither. I'd be leading the invasion.
Seriously, though, the odds of it being one of my species is so slim it's 2-D. So in the case of an alien race invading Earth, I'd probably be curious to find out what kind of people these aliens are, hoping they were benevolent to some degree.
2. The aliens have landed and they haven't blown the planet to bits, how would you react if they looked like us?
Not sure whether I'd be relieved or scared, to be honest. Humans are scary.
3. What if the aliens were disgusting looking (like a pile of rotten cheese), then how would you react?
I'd ask them about their biology, as I would be fascinated.
4. The aliens are about to make an announcement and all communication goes out. Your neighbor says that she/he heard that the aliens have announced they are going to destroy Earth. Do you believe him/her? Why?
Well if the aliens were any good, they'd postpone their announcement until communications come back on. And no, I wouldn't believe rumors.
5. The aliens have announced that they will share their knowledge with humanity if a certain person has sex with one of them and they call your name. To make it more palatable, the alien can change into any porn star that you want. Knowing that your partner will find out if you say yes, will you do it?
Yes, yes I would. And depending on their appearance, I might not even need them to take a disguise. I have occasional xenophillic fantasies. :-D
As to my "partner"... zie would probably either cheer me on or be jealous of me, or both.