Here's what I would do if I had the chance to take a hack at the album before they left the studio.
NLOTH: Something to lead into the song other than that drone note. And a vocal take by Bono that doesn't sound like it was taken from a demo.
Magnificent: Bring the second guitar up higher in the mix (this is a problem throughout the album), and rewrite some of the verse lyrics.
Moment of Surrzzzzzzzzzzzzzzzzzz.... (get rid of this dull, extremely overrated, way-too-long piece of shit altogether. What a waste of seven minutes)
Unknown Caller: The solo could be a lot more aggressive. The chorus is very repetitive and nonsensical, I would have them rewrite the lyrics at least. They don't fit the mood of the song whatsoever. And get rid of the "sunshiiiiine sunshine" part at the start - unnecessary.
I'll Go Crazy...: This song is mixed very well, and the chorus is great. The only thing I might do would be to make it sound like a bit more of a blowout at the start of the chorus (the "it's not a hill" part is great, but it could absolutely pop). One of the best songs on the album.
Get On Your Boots: It's pretty awful. Ditch it entirely. They can do way better than this for a lead-in single.
Stand Up Comedy: Again, bring up the second guitar in the chorus. Extend the solo section, there's a lot of potential there but since it's only about 10 seconds there's very little room to expand.
Fez-Being Born: Take out the "let me in the sound" in the Fez section and keep it either instrumental or get them to write something original. This isn't hip hop, there's no need for a sample. Make the transition better between the two sections. Take out the stupid xylophone backing behind the guitar in the Being Born section and get Edge to play the same thing on the low E. This should be a dark, aggressive song until the key change at the end.
White as Snow: Great song. The bass and guitar play off each other really well, and the subdued theme of the song is kept where it should be.
Breathe: Another excellent track, the only thing I would do is bring the rhythm guitar up in the mix again, especially during the prechorus. Oh, and get Bono to come up with something other than "ju ju man ju ju man" - it's a distracting lyric when everything else around it isn't.
Cedars of Lebanon: I wouldn't change a thing about this song. There's nothing overbearing on this track at all, and it's an excellent album closer with great, deep lyrics.
The best songs on the album are the last three, and I'll Go Crazy.
ETA: I jsut want to add that despite all of the above, I really do like this album (other than Moment of Surrender) and think it's their best work since at least ATYCLB, and most likely since Pop. But there are still some deep flaws and things that could have been improved if they had worked on it for a bit longer (and by that I mean not waiting so long to get into the studio).