Hi Phil,
Welcome to the forum!
In answer to your questions, RadarBox always displays North at the top of the screen, just like a real radar display. There is no way of changing this, but I have never found it to be a problem. With all RadarBox users having the same setup, it makes it easier to find traffic when it is talked about on the forum - and remember, you will be seeing traffic on RadarBox much further than you can see by eye!
When you ask about Flight Tracker, I presume you mean the RadarBox software? You can install this on as many computers as you like, but you will only be able to see live and network traffic (when you are connected to the internet) when the RadarBox hardware (receiver) is plugged into your computer. However, you can view recorded sessions which is good for demonstrating to other people when you don't have the RadarBox hardware with you.
I use my main PC at home with an internet connection, then use the laptop when I'm away from home.
I hope that this answers your questions.
All the best
Allocator
P.S. Phil, I'm in Shrewsbury but I can post some more screenshots if you like - I already have some in the Screenshot section of the forum.
http://www.airnavsystems.com/forum/index.php?topic=159.0