Oh dear, welcome to the world of I.T., I've possibly been talking about something completely different!
#1 or #2 I'd like, great idea. I've noticed when you are changing maps that you can scroll down and miss the correct map without realising, so good idea. Or #4, Maybe even say the top 5 frequently used maps could appear at the top of the list when you press on maps.
All of my other comments around favourite maps were specifically around downloading of maps, in the download section. In theory though if you had a checkbox in there for downloading favourites, then maybe those maps selected by checkbox could then be highlighted in another colour in the main map selection pop-up if you chose option #1 or alternatively they could appear at the top of the list as per option #2 or #4.