Hi Don. I can give you a personal opinion only about audio side. I love Audition too, and I used it a lot. Logic is not a replacement for Audition. Logic is a completely different software, much more composition-oriented. Audition, instead, has a “scientific attitude” about audio, and many great features of its waveform tab are simply unobtainable with any other software (mainly thanks to good old Syntrillium, certainly not to Adobe, of course!) The best option you have for “the great escape” from Adobe is going for Reaper. Reaper is “substantially” free and way more audio accurate than Logic, for sure! Anyway, in order to replace Audition’s spectrum features, you will want to add iZotope Iris 2 plugin to Reaper.
About Fairlight: I’m a Davinci Studio proud and happy user, and I obviously tested Fairlight a lot. It’s terrible: rigid and buggy (the plugins slots sector is absurd…) I really can’t understand how can be possible using it in a serious production. The worst audio software I ever used. Simply my humble opinion, of course.
About Affinity I can only say that up to now Publisher can’t handle plugins, and if you are a Blurb guy this could be a little point for InDesign. But it’s also true that if you are a Blurb guy you can always use their own software, right?
I hope I have been of some help.