The fastest way to drive the race should be 100%, with tyre degradation and pit stops associated with that pace not so high as to make driving at 80% a faster way to complete.
Disagree - it should be about as equal as possible, neither style should be significantly advantaged.
The ideal place to be is where the guy going 110% but taking an extra stop, really does need to be at 110% otherwise he might slip behind the guy who is driving at 90% but is making his machinery last better for him and saving himself the need of an extra stop whilst the guy at 90% really does need to be careful or he'll falter at the last hurdle as his machinery begins to feel the pressure.
The styles should compete, rather than one or the other be a complete waste of time to even try, they are equally valid styles of racing and having both sensibly competitive makes for fantastic racing as you watch the two strategies converge at the end of the race.