I'm really glad I didn't completely abandon/mothball my G4 MDD with 10.4.11 so I can still resort to using it when I need Pagemaker. Perhaps it's simple laziness on my part that I haven't been more diligent in mastering InDesign to the extent I have Pagemaker.
And speaking of your Flash CS6 launch woes, I now deeply regret not having kept bootable drives with previous versions of macOS. Under Yosemite I had complete CS4 functionality across the board, and with every macOS upgrade I've adopted, I've lost more and more features, functions, etc. InDesign and Illustrator both began crashing randomly with El Capitan, so I learned quickly to hit save every time I did anything.
With Sierra, Illustrator behaves much better, but I'm unable to install new brushes, etc., and InDesign crashes instantly if I hit the Print command, so I simply create a Postscript file and distill it for printing. Come to think of it, I can no longer install new brushes for Photoshop, either, and I've got a boatload stashed away and wishing I could put to work.
Since I've got external HDDs coming out of my ears, I'd love to find where I could download and install Mountain Lion, since my iMac and MBP will both work with that, and I'd have my entire Adobe library working as it was intended. Perhaps Honestone might be able to help me out with that. I know I can't download even Yosemite from the App Store. Don't know if they simply aren't available, or if Apple is holding a grudge against me and won't let me have access to them! (It ain't paranoia if someone really is out to get you! Not that I seriously believe that, but it sometimes smells like it to me!)
All that being said, I'm not touching High Sierra until I can be satisfied I have at least a couple of older macOS drives working, so Sierra is as far as I'm willing to go right now.
I completely sympathize with your problems with Pages. I don't even consider that to be a viable word processor, let alone a layout program.
Apple's never been known for its software library. I used AppleWorks and ClarisWorks back years ago, and I always preferred them to anything Microsoft. They did hit a home run with older versions of iTunes, but that's morphed into a boat anchor in its latest incarnations, and there were a few other applications they've released that were/are stellar. I've never used it, but everyone I know raves about FinalCut Pro. Heck, I'm still behind the cueball in getting a competent grasp on Premiere!