Welcome Doug!
Not sure if you remember me from way back when in Warbirds, but I came over with the advent of AH3.
Icons are in yards. So 1000 =3000'. The Plus and Minus are counter-intuitive to me, but I'm slowly breaking old habits and learning that - means he is closing on you (Positive Velocity of closure), and + means he is opening on you (Negative Velocity of closure). No + or - means you are near equal.
Little symbol represents country (vs unique colors) and they can be a bear to read.
You can control most anything....
I'm sending you a PM with a phone number and/or TS info ..much easier to talk you through it than type it all up.
Cheers and Welcome!!
Dobs