802.3ad is link aggregation. 802.11ad is 60 GHz WiGig.
I did not test link aggregation. It is useful only to create a higher bandwidth connection for use with multiple devices, such as multiple computers streaming from a NAS.
Yes, and that's my use case. I have a proxmox server with dual port Intel i350 NIC, which supports 802.3ad. I have several client machines communicating with VMs on this host, and the 1gb/s limit is irksome. Since 2.5/5/10gb home routers are not yet available at a price I'm willing to pay, 802.3ad would be an OK substitute. Well, it would be, if it worked on this router. I'll probably sell it and pick up an X10.