Mag was my starter and still my 3rd most used frame, your buff sugestion and quality of life changes are good and would help a little but the problem that I see is other:
1. Excalibur is the poster boy not only because of the marketing but in the game as well: "perfect for new players" is in his descripition(at least in Portuguese-BR).
2. There is no point on pick Mag if her is so easy to farm, even Excalibur is a bad option because you can pick a much stronger version for free(Umbra), Volt is the logic option between the three.
DE need to change that, I don't know how but there is no real freedom of choice and that sucks.