Andres,

1/ >>>>> "if I will need to edit the MenuGroup.cui file as well"

No, you don't need to edit it, but you use it just as reference to find out the names of menu macros (commands)

2/ >>>>>"I'm going to assume that it is the second line that contains F2 because it is inside the container "<!-- Custom -->"."

Yes, you are right. The other occurrences of Fx (function keys) are used together with other key - SHIFT, so the full definition of shortcut is 

 <KeyCombo accKeys='SHIFT' VirtualChar='F2' bUseVirtual='true'/>

That means you need to press SHIFT and F2 keys simultaneously to trigger event assigned to "MenuMacroID"

3/ >>>>> "dashed orange lines around the keys which I do not know how to type the abbreviation form for in the code"

You can use some of them as "Virtual keys". I already posted the full list of "Virtual keys" you can use in shortcuts definitions and rules of their use here. As about their abbreviation form, I will try to find out and post later.

4/ >>>>> "can you clarify why it is not possible to remap the other function keys (F6 ... F12)?"

No, I cannot. I just know that you can use them in AutoCAD for Windows, but on Mac they don't work. Maybe it is "by design", maybe it is a bug.

5/ >>>>> " How can I program double or triple clicks on each (and also see what each is set to in single clicking)?"

It is not AutoCAD related thing, so you need to try to find third party software which will allow you to assign actions to your mouse buttons on system level. To begin with you can look at SteerMouse software, if it will support your mouse you can even assign actions (double-click, etc.) to different buttons even on application level.