I feel like I always want to attack with the big guys so it's hard to defend the Planeswalkers
Making interesting decisions for your opponent means giving them hard choices about what they want to give up (yes, good discard means making your opponent suffer you're playing black after all)
Even one successful use is generally worth it, and if you have the means to shuffle your library through a fetchland like Misty Rainforest, a tutor effect like Worldly Tutor, or even another mana ramp spell like Skyshroud Claim, you can improve your odds of success dramatically
All of the new cards will be spells, lands, and creatures set on Ikoria, while any reprints could potentially be from anywhere within Magics pantheon
As usual, Starter Decks do not have a lot of copies of strong cards thus it will be up to you to fill the gaps