It unfortunately seems that there isn't all too much use in video games for half-precision calculations from what I read about the topic (it also came up with the PS4 Pro). Certainly not enough to speed up the code by a factor of 2, maybe a 10-20% gain is realistic if it's used to full extend.
Yeah, that's mostly correct. Mobile games make extended use of FP16 as their GPUs are just too weak otherwise, but PC/Console games do much less so, though the amount seems to be slowly rising.
The Nintendo eShop rating Thread: http://gamrconnect.vgchartz.com/thread.php?id=237454
The Steam/GOG key gifting thread: https://gamrconnect.vgchartz.com/thread/242024/the-steamgog-key-gifting-thread/1/