If you're looking for a competitive ETB list, Brago, Chulane, and Yarok are all much better in my opinion
#16 Lotus Petal - Silver Age At one point, I jokingly defined a broken combo deck as one that would run Lotus Petal if given the choice
It's also a decent alternative to running more tutors if you can't afford the good ones, since more cards drawn means more chances to find the card you were looking for
You can have up to 4 copies of each card, and its generally best to go ahead and include the maximum number of copies of each card to increase your chances of drawing the cards you want and to focus your deck on a specific play style or goal
While it's not a requirement to play the game casually with your friends, if you have valuable cards, or if you're playing in a tournament, you absolutely need to have them