I'll give it a go:
Boy -- themes of [...]
Boy
I'd say it's more about growing up, than about innocence and youth.
October
The turmoil of adolescent feelings having been dealt with on Boy, this about coming to grips with those feelings, then rejoicing. Also about the aftermath of the death of Bono's mom (as well as Larry's mom)
War
It's about conflicts, internal, external, about longing and belonging, about love under seige; not so much about WAR in the classic, big, sense, but about what conflicts do to people.
TUF
Indeed an art exhibit on nuclear holocaust.
The Joshua Tree
Anton Corbijn took them to a desert location for a photo shoot, after hearing about the name of the tree, Bono looked up the biblical story of Joshua and how the tree got its name.
Rattle & Hum -- line from "Bullet The Blue Sky".
They likened the experience of making a movie, to guerilla warfare. (BTBS is about El Salvador)
Achtung Baby = Warning baby (or rather beware! baby)
Don't forget it's in the lyrics (Love is Blindness @1:59) as well:
a litte death/without mouring/no call and/no warning/baby I need...
Zooropa
Name of the tour and song. Which came first?
They wanted to celebrate the 3rd leg of the ZooTV tour with an EP, for which they had already recorded Zooropa, the song. So the EP and tour were named after the song.
I personally think it is a metafor, since the song is an amalgation of commercials lyrically and several soundcheck jams musically (Streets, Zoo Station etc.), They used a title that refers to this.
Note that Zoo Station refers to Bahnhof Zoologischer Gartens -Zoo Station- in Berlin, also referenced in the movie "Wir Kinder vom Bahnhof Zoo".
That movie about teenage heroin abuse (a common U2 theme, ie Wire, RTSS) used a David Bowie soundtrack including a German lyric version of Heroes (Helden)
...while U2 recorded Achtung baby at the same studio Bowie used for the Berlin Trilogy: Hansa Tonstudio.
Cooperating on those Bowie albums and co-writer of Heroes: Brian Eno!
Pop
From the dictionary definition: "a crackling noise"
All That You Can't Leave Behind
It's about mental luggage. Burning bridges, starting off with a clean sheet.
How To Dismantle an Atomic Bomb
Bono realising it is impossible to dismantle an atomic bomb (Bob Hewson's death) AFTER it has already gone off...
It's interesting that only 4 albums are named after song-titles (October / Unforgettable... / Zooropa / No Line... ). You would logically assume that the song came first and the album-concept later, but I bet that's not the case with the last three of those four (and maybe not with "October" either).
You are overlooking the pivotal use of lyrics such as:
Achtung Baby in LIB,
ATYCLB in Walk On,
Boy (stupid boy) in Elco.
(here in the desert) TDAAB in Fast Cars
In all of those cases the titles of the songs could've been replaced by the above lyrics.
R&H in BTBS,
UABRS in NYD
etc.
These album titles were just "waiting to happen".
There's an interview with Adam - It's from that Classic Album show and he explains it... I like the story about Anton Corbijn pronouncing it "The Yoshua Tree" and how they kept getting him to say it because they thought it was funny 
