It's a sassy puzzle, really. The kind of upstart that likes to show off its knowledge. Like those "children who are up on dates and floor you with 'em flat."
Okay, actually, Mr. Livengood has produced a fine example of a Monday puzzle, with six theme answers that doesn't sacrifice the fill too much. Each of the theme is a reasonable phrase, although I'm not that fond of PERTPLUS, which is more of a brand name. FORWARDPASS is seasonable, given the big game coming up on Sunday. And I like "forward" as a synonym for "fresh." I like "froward" better, but that's archaic.
In fact, the worst piece of fill comes at 1A: Attendees (GOERS). The only time I've ever heard this term is in Monty Python: "Is your wife a goer, know what I mean?" Otherwise, it's a sad non-starter. Other answers on the same level include RUER, PARER, RISER, sort of. Things improved somewhat after that.
ERIECANAL, PADDYWAGON, SENIORPROM, and LEMONTART are all very nice long down answers, each crossing two theme answers, which does tend to put handcuffs on what's possible elsewhere.
You know, the more I look, the less I like the fill, which is too bad. I actually enjoyed doing the puzzle, so maybe I don't want to nitpick too much. Let's just say that OOO is not something I like. But at least Jean-LUC Picard is in there. And Hieronymus Bosch.
So, a mixed bag.
I, too, like "froward," and I dislike all that you called out in this one. ("It really doesn't matter [which ones] you put upon the list, for they'd none of them be missed, they'd none of them be missed.") As I was doing it, I cringed a few times, and I didn't really take the time to realize what the theme was. Now that I see it, I like it all right. Meh. It's Monday.
Nice answers in here, among them ILIAD, LUC (previously-mentioned), COSMO, POT and KLINK. I'll give you GOERS and will add to that APISH (26A Copycatting); both sub-par. But I liked that FORWARD is just below YORE (43A Days of ___ (past times)); unintentional? Maybe. And what about FLIPWILSON?! We certainly don't see nearly enough of him nowadays.