Am I stretching my ecoboost limits?

Kevin O. wrote:
You will find yourself building up speed going down steep grades and end up having to ride the breaks hoping they don't overheat by the time you get to the bottom.

Don't ride the brakes - they will overheat. Use the brakes to slow down then let off to let them cool. Then when the speed builds up again use your now cool brakes to slow down again. (Or get a suitable TV.)