Wanting to check my interpretation here.
Whenever a terrakineticist gains a wild talent that isn’t a universal talent, she chooses one wild talent of the appropriate level from each of the six elements (aether, air, fire, earth, water, and wood). She can use wild talents of the same element that she chose in this way to meet prerequisites for these wild talents. Instead of gaining one kineticist blast, a terrakineticist chooses one simple blast from each element that has more than one simple blast.
Reading 1: If at any level I choose to gain a universal wild talent, I then don't pick different talents for each element. So at level 1, I can pick a universal infusion such as kinetic blade, OR I can pick one non-universal talent for each element (for example, pushing for aether/air/earth/water/wood and burning for fire), but I can't take kinetic blade for earth, burning for fire, and extended range for all other elements.
Reading 2: Any time I gain a talent that isn't specifically required to be a universal talent, I can pick a different talent for each element. In this case, could take both burning (for fire) and kinetic blade (other elements) at level 1, but since for example the 7th level talent is specifically universal for a terrakineticist I pick only the one talent at that level.
That would make character building a little more straightforward because the talent selections would be independent of each other.
On the other hand, it seems a bit odd that a terrakinecist could lose a universal talent when moving between terrains, if they didn't pick the universal talent for all elements.