Sorry, an alien, I am actually america, and struggle with Portuguese

Native English speaker here.
At any rate, I think examples of cards can stand without needing to be balanced, they are just examples for what can be done, not something that time has been put into to make sure its right.
If I may take an example of a game mechanic that has been added to new elements recently to show how it can make things interesting...Dune scorpion.
Time...with poison? Seems wrong. Death, yes! Life...ok, it had that shield already. Time, though? But how well does it work? The answer is...beautifully! Poison is a pretty simple way to do damage in the game, allowing damage without the use of the creature staying on the field, but the dune scorpion works perfectly, not only as a rather powerful poison causing creature, but to work WITH time's existing theme.
They "slow down time" by forcing your opponent to play fewer cards, or take increasing poison damage. But time also can reverse time for the enemy, or speed it up for himself. The card has perfect synergy with both of these, since the scorpion needs another card to attack, and cards going back to the deck force them to be replayed, making for more poison.
How awesome is that time can get a poison mechanic that fits perfectly with everything else? I can't imagine poison as part of a time card would have gotten much support before the addition of the scorpions (and it fits much better than the discard from the hand, with the current cards surrounding it).
Now, with that in mind, we can come up with ways for many elements to get some of those game mechanics that would seem perfectly natural. Let's do something that seems to totally counter everything we know about elements, as it stands, death healing creatures. How about we make a death card permanent, which, has an ability that can be activated for

, which will remove poison from the target creature and heal all of your creatures by 1.
This fits the theme of death, working with poisons and other deadly materials, and gives them the ability to heal creatures, something death currently lacks. As someone that studied pharmacy, I also have to like how by diluting the poison, you get medicine...but maybe that is where the idea came from

Is it balanced? It doesn't matter, its just an example of how even when it seems terribly contrary, it can be done without doing something insane.
As for when its time to do this, I think, and hope, its something that can be done little by little. There is no need to work on a whole host of these at once. If one card that can heal a death player is added, then one card that will allow entropy to draw extra cards is added, then one card that lets aether destroy permanents is added, we end up at the end with the elements able to stand alone.
No reason to rush, but, at the same time, no reason the process can't start now (as if it hasn't started at least a bit already).