Everything may well play out the way you describe, but I strongly disagree with this sentence.
Both sides of the garage want to see their driver win, yes. That's called encouraging competitiveness in a competitive environment. But both drivers will still have full go at each others data. There will absolutely no division within the team when it comes to data, parts and developments. I can only repeat myself, whoever tries to withhold something from someone else in the team, and this goes for absolutely everyone in the team, is a goner. Period.
Nope. You want to finish first, you gotta finish first. Who says there wont be an accident while lapping? Some technical failure? WIL showed in Monaco, that even MER engines can break. Being clever and collecting 2nd places may well be the ticket to the WDC.