Can's say I disagree with you. Would be great to have those features added. But what you propose, is a lot of work!! And there are only so many hours a day, so unfortunately I don't think that it will happen. You know, I've also a real job.... :-)
On your remark about the window repaint waiting for the fetching of maps, this program was always meant for people doing map downloads from a normal desktop with standard fast internet, which happens in split seconds. And when you're then on the road, the maps come without any delay from your harddisk. That was how it was designed to be, I understand that things will be different when you use it in different ways, like not "pre downloading" maps but (while on the road) downloading on-the-fly using some slower wireless connection. Yep, in that case, you need to have some patience.
Summary, if this is not the right program for you, just use something else. Your choice .....