I'm no expert on ETOPS, but I seem to remember that maximum diversion times above 180min (ie, 207, 330 etc) are based on actual winds, whereas the "traditional" ETOPS (up to 180) is based on still air.
No.
And for a simple reason - the time is arbritary in terms of safety (i.e. ten minutes here or there doesn't affect the safety case), and the point of each of the limits is to open up specific over water routes. That's why it's "still air" - so that you can draw a circle on the map, and approve the route. If that circle had to change with wind, then you'd have to cancel sheduled flights based on the changing wind each day, which would be a commercial nightmare. So, no, it's always a line on the ground, a still wind calculation.
Of course, planning the flight on the day, you have to account for wind for the fuel uplift - so you have to calculate your single engine burn from the Single Engine Critical Point using the Single Engine cruise speed and fuel flow you used to get the approval and the actual wind for the flight on the day... but that doesn't affect the approval of the route.
ISTR that a 747 out of LAX or SFO (I forget which), destination LHR, lost an engine on takeoff and, with plenty of options in North America before they committed to the pond, the crew elected to continue rather than hang about dumping fuel and land back.
Which is perfectly reasonable (and one of the justifications for four engines) - once you lose an engine, you are now a three engine aircraft. You are still subject ot the same rules to continue - if you lose one engine (the critical one) you must be able to, at any point on the route, divert to an acceptable airport without running out of fuel or descending into a mountain. So, if you lose one in a four engine aircraft you run the numbers for losing the other one on the same side and check your two engine ceiling against the lowest safe altitude, and the work out the two engine Critical Point for the route and work out the two engine fuel burn to your acceptable alternate. If both of those calculations are still good (and they normally are - the limiting thing is take off performance, and you are generally already airborne) then you are legally OK to continue.