So busy slapping 'em together that I hadn't posted I'd updated 'em. Here's the last few updated scripts (October 29 - November 8):
Set Video Kind of Selected v5.0 - change the video kind property of the selected tracks to your choice of "Home Video", "Movie", "Music Video" or "TV Show". Additionally, "Show Name", "Season Number", and incremental "Episode Number" can also be set or cleared for each selected track.
Convert and Replace v2.0 - convert the selected tracks using an encoder chosen on-the-fly (the encoder's current Preferences-set options will be in effect) and replace the originals throughout the playlists of your entire library with the newly converted versions. Additionally, you can opt to Trash/delete or keep the original files and tracks.
Trackographer v4.0 - stay-open applet will monitor iTunes and send tag and time-of-play information of each track that plays (including iTunes Radio and internet radio streams if they provide track info) to a text file. Preferences can be set to include or not include various basic tags and to create a plain text file or a tab-delimited text file which can be imported into a spreadsheet.
Multi-Item Edit v2.1 - mostly bug fixes; edit most track tags (and some additional options) in a single window which emulates the pre-iTunes 12 "multiple items" format; that is, a checkbox adjacent to each tag allows you to select which changes are to be applied to the selection's tags.
Delete Selected Files v2.0 - remove each selected track from all playlists and Trash or immediately delete their corresponding files. Some iTunes delete commands will not move files from outside the "iTunes Media" folder to the Trash. This script worksaround that.
Find Truncated Tracks v2.0 - assists with segregating iTunes Match tracks that appear to get cut-off when played (due to a possible bug which Kirk describes here). Then these truncated tracks can be deleted and re-downloaded intact (by you, not the script).
Playlist Manager v2.0 - iTunes only allows one playlist to be selected at a time. This applet can perform common useful tasks on a multiple selection of playlists: rename (add text, remove text, search and replace text), duplicate, delete, export, merge.
Search Results to Playlist v2.0 - search a chosen category (Library, Music, Movies, etc) or the selected playlist for user-entered text by All, Song, Artist, Album, or Composer tag and copy the track results to a Search Results playlist, which will be created automatically if necessary. Can optionally re-create or append to the Search Results playlist on each run. Floats over iTunes while active for easy access.