@eternal Re point 3, if either your or lightbearer's option is possible then I'd prefer lightbearers as it would distinguish better - e.g. an astro player joining a setons game with the colour coding system that treats them the same would at first glance be the same colour as a setons pro despite the astro player likely severely underperforming their rank.
Some time ago a suggestion came up about having the number of games a player has played on a specific map being shown (alongside their total games), which would be another option if possible. One issue with ideas around showing how good someone is at a particular map type is the variability of map names, so the benefit of 'just show number of games on this specific map name' is it avoids such issues and means that for the most common maps (i.e. the most popular variants of DG and Astro, and setons) you will get a good idea of how experienced the player is and be able to better balance.