Just go ps4 only at launch with a pc release 1/2 years later. A large chunk of the small xb1 sales will get it on ps4/pc anyway so you really aren't missing out on much.
If Microsoft paid for the xb1 port then I'd give it to them.
No, the large chunk of xb1 sales won't buy it on ps4/pc. Almost all xb1 sales come from the people who want this game on Xbox not any other platform.