Hasie I use the pipe to show when 2 (or more) chords are in 1 bar. A lot of people just play with the song and ignore them.
Capo means put capo on 2, play the open G shape (which now is actually an A).
You are correct about Whats Up. that's how the band played it originally.
For halleljuah, that is how they are usually given. So transpose away, it should make the overall sound a lot richer.