So I've been compiling the flavor texts and organizing them by charater and issue and I have some observations.
The Freedom Five Comic's didn't come out every week. There are characters who start in Annuals (as per their bios) who have speaking lines in Freedom Five, less than 50 x the annual number they came out in. (For example Unity debuts in F5Annual #11, but she has a speaking line in F5 #540. If F5 came out every week then F5 540 would be released after ten (10.38 to be exact) years, but instead it is released after the eleventh annual.
Mystery Comics likely came out monthly, Visionary appears in Mystery coimics 291. Her first appearance is in F5 annual #16 (as per bio). Which is way too early for her to show up if mystery comics was on a weekly schedule. On a monthy schedule Mystery 291 would have been runing for 24 years, minus a few before Freedom five (at least two because of the two Freedom 4 annuals) probably more because the F4 annual 1 assumes we know who Legacy is. Additionally Mr. Fixer appears (for the first time as per bio) in Mystery comics 145, and also in Freedom Five 617, the timing of these, is reasonable to confirm the timeframe.
The Freedom Five Annual #6 introduced both Nightmist and Gloomweaver, It is likely that the plot revolved around these characters.
In the Freedom Five annual #11, Ambuscade likely incapacitated a good number of the heroes and Unity (a new character) likely saved the day.
Akash'buta's first appearance is in Prime Wardens #1 (as per her bio), yet was likely also the main Villain of F5Annual #10 (Implied by the flavor text/picture combo of "By any means")
There may be a Typo in the flavor text of the scholar's card "Mortal form to Energy" as it comes from the comic "Tomb of the Bizzare" which is never mentioned elsewhere. However "Tome of the Bizzare" is mentioned many times. I think they are likely supposed to be the same.
It is likely that Expat, Chrono-ranger, Fanatic, Nightmist, Ardent Adept, and The Scholar appeared in the multiverse before Grand Warlord Voss. Based on the Flavor text of Hairtrigger reflexes, Expat likely helped with the defense efforts.
Fun Fact: Visionary has a line before she is introduced. She is quoted on Mr. Fixer's card Meditate in F4 Annual #15, but her bio says her first appearance is in F4 Annual #16
I may post more as I figure more out.