Would love the option to change font style (especially size, but also style (normal, bold, italic) and maybe even typeface.
I'd be willing to make a PayPal donation towards this too :-)
Using arbitrary font styles (changing the on the fly) is harder than it seems. But if all you need is a nice final image, you can export a map into SVG and change font settings there.
Different person but if the font size was tweaked for large/medium cities so that there isn't overlap that makes the text illegible that would be extremely helpful.