MitchThe playoffs would likely have to play on a weekend to work with everyone's timezones, but this would be no different to if the teams were at LAN.
At LAN you don't have to wake up in the middle of the night to play. You will most likely have adjusted to the jet lag in the previous days if you come from other continents. Waking up in the middle of the night vs being jetlagged is a big difference.
MitchYou're right, it would be hard to compensate the ping but if measurements were done to find the best server at least it would be even. Nations cup is an example of where they've managed to do it.
The ETF2L nation cups are played on European servers at European times, so anyone not from Europe is very disadvantaged. It's a European league, so the nation cups are mainly for European countries. It is not really meant to be an intercontinental competition. North American teams usually get Chicago/East coast players for ETF2L competitions as it's possible to get below 100 ping, which is still playable. Oceanian/East Asian teams have never entered as they would have to wake up in the middle of the night to play a 300 ping official.