War-"Slippin’ Into Darkness"

Pat, my mono commercial 45 does have an actual time of (4:15), as you currently note in the database, but the listed time on my 45 is (3:49), not (3:59), as you currently state. My commercial 45's deadwax is "K-1157 UA-8705". Also, I have two different promo 45s for this song, with all versions of both promos in mono. One promo, that has "Slippin'..." only on one side, has a listed time of (3:59), and an actual time of (4:15). Deadwax is "K-541 UA-8705-16". My other promo 45 features the same listed and actual (3:49) version on both sides, with deadwax of "K-1088 UA-8705-Rel DJ" on one side; the other side of this promo 45's deadwax is the same, but ends with "UA-8705-DJ-Re 1" instead.   

Do all the 3:45 DJ edits listed in the database run faster
than the 3:49 actual DJ 45 or do the CD's fade 4 seconds
early?

After comparing the version on Best Of War & More to the promo 45, it seems like the database will need to be updated. The version on this CD that runs 3:45 is actually the "dj 45 edit, but missing the first 1.5 second opening keyboard."

Furthermore, it sounds to me like the promo and stock 45s have a dedicated mono mix, although the differences are subtle. There's nothing that majorly stands out when comparing it to a fold-down of the stereo, but the level of the vocals and percussion is ever-so-slightly different between the two.

Most likely, yes.