Tokens can be Tributed or banished to pay costs or fulfill Summoning procedures (such as for the Summoning procedure of "Destiny HERO - Plasma" or "Unibird"), unless they would be required to be banished face-down (such as for the activation cost of "Hypernova Burst")
For a very solid and highly detailed look at this aspect of MTG collecting, I recommend this fantastic article by Guo Heng Chin
If a Level 3 or lower Zombie monster(s) you control would be destroyed by battle or card effect, you can discard this card, instead
Pokemon TCGs explosive popularity currently has new cards in short supply
Otherwise, there would be the option of buying the Premium Pass to get more boosters and benefits
Except for the type of cards that power-up monsters or Field Cards, these cards are destroyed after use, and cannot be used again