Yes, it does exist. There's a reason big towering corporations play a big part in the film. Every time you see an ad you're essentially being incepted. Nolan's making a point that many of the things we do are not actually are own ideas or wants. We're constantly told what to do and we think many of our beliefs our owned by us. The truth is that people are constantly being incepted.
Hello! I love Inception too, this is my favorite movie of all time.
And about questions:
1) Yes, but not exactly in the same form as in the movie, but yes, it exists.
2) Yeah, I would love to try it. Like Nolan himself, actually, when he was writing the script for Inception, it would be great to try something in that sort of thing.
1. Yes. We do not see things as they are; we see things as we are. -Talmud
2. Yes. Although no distinction between conscious and subconscious action i.e. Inception. Everything is relative to everything else.