If its a childhood card with a bite taken out of it, its not likely to hold as much monetary value as a pristine copy thats been sleeved and stored nicely
These lands that can enter untapped if any player is down to 13 or less life, which benefits aggro decks, but by then, basic lands might be just as good
Tell me the color and mana cost of a creature, and I can tell you if I have it
Since then, dozens of individual cards can lead you to immediate victory
Cards that care about discarding, like Waste Not, only work with effects that explicitly discard a card from somebody's hand
Now that card sleeves are required and cards rotate in and out of a Standard play environment (to help solve for Garfields concerns) it truthfully may not make that big of a difference