Hello @chingchung
1. Does 88W8801 can suport wifi channle 14 in Japan ( We know 1-13 should be no any problem )
From 8801 datasheet, Table 14: Channel Frequencies Supported
channel 14 is not supported.

2. Does 88W8801 can support ad-hoc mode ?
No, it doesn't.
But 8801 supports Mobile AP interface, it can be used for Access Point.

3. Does nxp can provide 88W8801 driver for Microsoft azure rtos ?
No, we only have driver for FreeRTOS on MCU platform.
Regards,
weidong