Sorry, I read your #2 part first.
I think it's the Indesign PDF that's the culprit. I've had other issue with those. They sometimes seem to contain things that other app's than Adobes, and even Adobe Reader, doesn't like.
My first suggestion would be use a simpler program than Indesign to create your specs. MSWord, for example, or even Apple's Pages.
If that isn't possible, try polishing your Indesign PDF by opening it in Adobe Acrobat (full) and use the Reduce Filesize option to re-save it.
But my recommendation is to reserve Indesign for advanced layout tasks. For a simple spec sheet, Archicad's own formatting works fine for me. So I can write in any simple text editor if I like.
AC4.1-AC26SWE; MacOS13.5.1; MP5,1+MBP16,1