I need to share a template with another organization. The template needs two macros that the other group will need to use. So I add the macros to the template and assign hotkeys to them, specifying to save in that template. When they create a new document from the template, can I be confident that those hotkeys will work for them? (I'm using very unusual key combinations that are unlikely to be already in use.)

Assuming that the macros in the template are enabled, the hot keys (keyboard shortcuts) will work in any documents attached to the template. If they are also using Ribbon versions of Word, you can also attach QAT icons to the macros.
Modifying the QAT and Ribbon in Microsoft Word