I am using Sierra since the first beta and filemaker always in the latest versions I dont have any of the problems you mention (Applescript I am not using it) maybe is something else that causes your problems?
I'm using FMP 14 on 10.12.4 with zero problems.
In fact, I've never had an FMP issue with the Mac, compatibility-wise (other than bugs) in the last seven years - since FMP v. 11. I can't recall a single case where FMP has crashed. I've had infinite loops due to my stupid mistakes where I had for force-quit FMP, but that's not FMP's fault. (FMP then deleting the watch expressions from the plist is one of the bugs I alluded to, but that's another matter.)
Maybe try creating clean Mac a Virtual Machine for an FMP 15 install, or making sure that FMP 14 works OK.
Any errors in the Apple error log?
could be an issue with fonts, with Acrobat (there are known issues with both...)
although upgrading the OSX works fine most of the times, we've had it that some older files/settings left the OS in a bad state - we reinstalled the OSX from scratch (vanilla...)