Mine also doesn't import all the Adobe fonts it ought to. I'm guessing this is Adobe's death knell for Fireworks...
I un-installed Fireworks, then followed the instructions from Pablo on this thread (Unable to install Fireworks CS6 on Mac OS X Sierra ) to reinstall... still a bit slow but at least I have all fonts again.
My issue is that Fireworks will not open a file when you use File > Open or File >New from Template.
I have reinstalled made no difference. Fonts are working OK. Sadly it looks like the end of Fireworks CS6, interesting alternatives for an iMac are Affinity Photo and Affinity Design.
If anyone has found similar issues with Fireworks CS6 and found a solution I would be grateful if you would share.
Funny enough, the day I posted this. I found Affinity Designer. The function is just like fireworks, but 10 million times faster, easier and cleaner.
If anyone find this post. Please try Affinity Designer. I am really sorry to hear Adobe continues to kill some product I loved, such as Edge Reflow and Fireworks. I used fireworks since Macromedia Fireworks.