If you have a 2011, you were definitely right the first time - 70% is 70% of life remaining, not 30%. You have to push and HOLD to perform the reset, just selecting it won't change anything.
Ford only has one set of oil change intervals for the F-150, and they are the same in both the USA and Canada - it's up to 10,000 miles (or the metric equivalent) or 12 months as indicated by the IOLM display. PLENTY of dealers are finding any excuse in the world to have you come in sooner since 95% of drivers aren't going to make the indicator trip before 10,000 miles.
The IOLM sensor will reduce the % of oil life based on how you drive the vehicle and the conditions it is driven in - unless you drive it like a madman it won't drop down faster than 1% per 1000 miles.
Note that the only condition it can't sense is excessive dust - driving extensively on dirt roads is the example in the manual. If you do that, then the oil change interval is every 5,000 miles or 6 months. I would like to point out that finding a dusty dirt road in the winter time is just about impossible since snow "dust" evaporates.