yes

I wouldn't doubt it.

No... or... I dunno, maybe?

There's a lot of stuff we don't know.

There is definitely life outside of Earth. And why do scientists always say they need water/ oxygen to live? Why does all life have to need the same nutrients to live?

Possible, but I doubt it.

1) Humans have found no evidence of ET beings on Earth (fossils, spaceship remains etc).

2) There is no Planet anywhere near to Earth that is likely to be able to produce intelligent life.

The planet would need to be close by unless they had figured out how to get around not being able to travel faster than light. If the planet was more than 100 light years away they probably wouldn't make it to Earth (alive).

yes I do

1. I definitely believe in aliens, they have to exist.
2. Have they visited earth? I can't say, how could we tell, they would be very covert in doing so.
3. I believe that they would definitely know about earth if they did, let's face it they are likely far more advanced than us and in maybe 200-300 years we know about life on other planets.

True, we haven't found a planet yet, but gravitaional lensing does not allow us to detect planets that have the same conditions as earth, so we really don't have a clue. Who knows maybe every other solars sytem has ten earth like planets and we are the odd ones out. As we have seen from other solar systems already, we are a bit of a freak solar system.

Also, who says life needs earth like conditions to produse intelligent life?

I´m with Kasz, in that I don´t believe, but I wouldn´t be surprised to be proven wrong.

Nevertheless, I´m fascinated by stuff like that....one of the most controversial cases to this day is the Billy Meier UFO encounters.

This site has a lot about the case:
http://www.theyfly.com/

Yep theyve been, i believe it