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.

Long-press the profile button in the toolbar.

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

Ideally there would be (optional) columns, like slide_ios did on the iPad:

And when swiping from the left you even got the subscribed subreddits ("Traverse" view in Memmy):