I don't think this has an effect anymore.
Basically if your taxes are due on the 17th your payment already needs to be in the mail by then and you can't sell in the last few days.
It takes a while for the exchange to process your withdraw, you wouldn't do this last minute. Plus there could be bank delays.
I believe the same.
I don't think this has any effect anymore. Predicting something out from this localized regulation doesn't have any global effect and way too easy to predict. Which would mean that many would have countermeasures by then to prevent this highly predictable drop.