Thank you for commenting on this @morris0 ... I appreciate knowing that you found it valuable, and I hope it helps you as you get your start here. I also want to welcome you and let you know that I'm always happy to help you. So stay in touch and ask me anything you want.
The one thing you asked about (witnesses) I think is something that we don't need to think about at our level. Basically witnesses are the ones that over the network and make sure it is running properly in all aspects (both hardware/software as well as rules)... I think it is important, but just not until you take care of mastering the other things necessary to be successful. I myself have voted for only 3, but frankly we're both so small it won't matter for now.
Also I want to make sure that you see the other 3 articles in this series, because they are all written to hopefully help someone exactly in your position. Those articles are linked at the bottom of my article with hyper-links...
It is nice to meet you and I am now connected to you, so stay in touch my fellow 2017 classmate!