sticking to just one Energy type is often best, though this can leave you vulnerable if you happen to come up against a deck which is a type your Pokmon have a weakness to
Prismatic Evolutions has different set composition, different pack structure, and has been supply-constrained since launch
Creatures in Un- games with power between 0 and 1 still deal damage equal to their power, and players can have fractional life totals
Obviously, they dont have the space to cater to TCG-events, but Im not sure why they wouldnt try to capitalize on graded singles and sealed, seeing how it appears that Costco, Wal-mart, CVS/Walgreens and Target appear to be the current benefactors of the everyone buying and holding modern sealed
There are also cases where cards have abilities that turn them into a new type
You can only exchange cards you have at least three copies of, so there's no chance of accidentally getting rid of cards you need