Hello,
A1. you can check the linux reference manual for general PCIe support and how to make it run:
https://www.nxp.com/docs/en/reference-manual/IMX_REFERENCE_MANUAL.pdf
A2. That device is not supported and we have not the configuration at hand but you can ask the manufacturer how it enable.
A3. All the dependency are on yocto BSP and if you installed you don't need anything, if your wifi requieres more please check with your vendor.
Regards