Her +1 loyalty ability serves as good pressure on the opponent while also potentially filling your graveyard with more Zombies
Chaos Warp is a fine start, with the mystical archive version being worth about $6, according to MTG Goldfish
Honestly, when I think of Punishing Fire in the context of current Modern, it's either laughable (against Primeval Titan, control, Crashing Footfalls, 3/3 Dragon's Rage Channeler, reanimated Archon of Cruelty, etc.) or potentially even a positive, as a repeatable answer for the repeatable cheap threats from various Lurrus of the Dream-Den decks
Sword of Sinew and Steel Sword of Sinew and Steel lets you destroy a planeswalker and an artifact each time the equipped creature deals combat damage, which is essential when playing against superfriends or artifact decks