You'll be fine. Round 1 is simple enough. Round 2 boosts your primary weapon damage in a way that nullifies your level disadvantage. Rounds 4 and 5 have elemental burns which also boost your damage output.Is doing PoE 34 with a 33 character advisable?
You'll always be a little more vulnerable so you can't Rambo it but it's totally doable. I'd say most people running PoE 34 until next week will be 33s.