Re: Servicing.
You should be ok if genuine parts are use, the question is how do you know a non franchised garage is going to use genuine parts? you don't and also do they do the same quality of service or skip a few bits?
Then there is the question of vehicle recall some of which are dealer notification only, not bad enough for total recall to owners direct.
yes they may be a bit cheaper but while under warranty I would stay with a main ford franchised dealership.
Like most businesses if they can and do find out it has been serviced by non franchised garage and something goes wrong under warranty they could blame that garage and your warranty will be void.
Having bought many new cars over the years I have always gone back to the main dealer for service
Take my Nissan Xtrail still just under warranty, that was recalled as the front sensors detected that the auto breaking may not have worked on a shiny road surface.
Another garage would not have possibly known that as it was a dealer notification passed on by the dealer to their customers only and consequently booked in for rectification