I like the idea, but some of these make little sense under the title of 'elemental master'. Like how would almost decking out show you have mastered your element? If anything, your score should be penalized for that...
I wouldn't mind seeing additional elemental mastery possibilities based on each element. Like a time mark winning in x amount of turns, or a fire mark achieving x amount of attack points on the field, or life healing x amount.
And so on, they would have to be hard to achieve, naturally, but would add a tiny bit of strategy...