Yes, it's possible.Go to a community's or user's page and in the upper right corner there are three dots, in that menu is an option to block.
There are solutions for Thunderbolt that allow connecting external graphics cards (eGPU) like this one from Razer, but the typical docks just forward the signal. Edit: Updated link
Yes, it's possible.
Go to a community's or user's page and in the upper right corner there are three dots, in that menu is an option to block.