Is sending money from your bank account using Zelle to buy crypto on a P2P site considered safe?
if you buy coins from a reputable user on a site like localbitcoins---and use their escrow system---it's safe, yes.
when it comes time to sell your coins, i recommend against accepting zelle though. there have been lots of chargeback scams with zelle where the sender claimed their bank account was compromised, rendering the zelle transfer fraudulent. zelle and your bank will claw the money back from your account. this has even happened with trusted localbitcoins users whose profiles were hacked/sold and then used in combination with a chargeback scam. always be cautious selling cold hard coins for digital fiat!