Firstly the active grille - I doubt you will experience much difficulty in practice, so I wouldn't be concerned with it now.
Secondly, what is the exact code you are seeing regarding the ECM? (to Ford its the
PCM)
The 120k Ford service must have been before you bought it. You can't be truly 100% sure that the trans fluid actually did get changed, even if it was paid for
What do you know about the previous owner? Was the fluid changed at 60k?
You could get a mechanic you trust to check the condition (colour) of the fluid, although having done 15k since the change it probably won't be conclusive as to how new it is.
Out of interest, is this the 'facelift' model? ie is it MB or MC?