Why can't I edit album track information in the INFO window, and more to the next track without having to do each track seperate?

Either select a single track, Get Info, then use the Next/Previous buttons to move between them, or select multiple tracks, Get Info, and edit common properties. The next and previous buttons do not appear in multi-track Get Info (and never have).

Regarding duplicates, Apple's official advice is here... HT2905 - How to find and remove duplicate items in your iTunes library. It is a manual process and the article fails to explain some of the potential pitfalls.

Use Shift > View > Show Exact Duplicate Items to display duplicates as this is normally a more useful selection. You need to manually select all but one of each group to remove. Sorting the list by Date Added may make it easier to select the appropriate tracks, however this works best when performed immediately after the dupes have been created. If you have multiple entries in iTunes connected to the same file on the hard drive then don't send to the recycle bin. Use my DeDuper script if you're not sure, don't want to do it by hand, or want to preserve ratings, play counts and playlist membership. See this threadfor background and please take note of the warning to backup your library before deduping.

(If you don't see the menu bar press ALT to show it temporarily or CTRL+B to keep it displayed)

tt2

No idea. I'm running 11.1.3.8 and they are there for me to the left of the OK and Cancel buttons. Perhaps a repair install from the programs and features control panel would help.

tt2

Ah, it may help to use the Songs or List views rather than Albums. In the albums view you can only work back and forwards through the current album, which if it only has one track means no next/previous. 😉

tt2

You're welcome. 🙂

Library tidying tips at Grouping tracks into albums.

tt2