2) Also on our (long term) firmware roadmap!
3) It would be extremely difficult to damage the internal USB-C ports from force on the USB-C Expansion Card. You'd destroy the USB-C Expansion Card first, which is inexpensive to replace.
4) This is a great question, and actually on our list of blog posts we want to write. I don't have the answer off-hand, but it shouldn't be different than other recent Intel-based notebooks.
5) Currently we're limited to offering it to repair shops, but we're looking at ways to expand that in the future.
6) For the Expansion Cards, since they are standard USB-C devices, you can plug them into other USB-C hosts (though as you note, they are somewhat oddly shaped for that). We've also released open source CAD and documentation for people to develop their own Expansion Cards.
7) The heatsink and fan is custom to the system by form factor necessity.