Tournament e-Boards

There are 6 questions
Can I use a (very) long USB cable for my DGT e-Board?
Can I connect a serial e-Board to a computer that has only USB-connections?
Why is my DGT serial e-Board not recognised by my computer?
Why does my USB-connection show up as a com port?
Why is DGT not selling tournament boards with serial connections anymore?
How to make a tournament set up