Adding Columns to Admin
To answer your first question, I recommend a plugin called Codepress Admin Columns. This is by far one of the easier and non-coding ways to implement columns. But it will set you back 15EUR to purchase the add-on that allows sorting.
If you wish to get your hands dirty with code then this post by tzeldin88 will help you get started.
Filter Posts from Dropdown
I will update when I get back with some articles that I do find pertinent.