It's fine to throw in a few powerful cards just because they're powerful - which is why Sol Ring has a reserved seat in pretty much every Commander deck ever - but usually the best result, and the most fun, comes from crafting a deck that's a specialised, synergistic machine
For the same reason, you typically want to ensure your sleeves are fully opaque and you cannot see through them
Each target must receive at least one +1/+1 counter
The number you run is to taste, but a general rule of thumb is that using more board wipes will mean games take longer
Because Ashaya makes Bumi into a land creature, you can easily set up infinite combat steps for Bumi and your other land creatures
Since the deck is built around making tokens, youll essentially be able to draw an extra card every turn