I'm currently playing minecraft with cracked multimc launcher but I don't know if that's legal or not. Is it?

idk but 80% it not

no

no. An instance of this is the dreamingarturzz claimed to be FWR 9:01, which, not talking if it's fake or not, is unverifiable due to the cracked MultiMC. Just use offline MultiMC, it's legal in my knowledge.

UltimMC is not allowed, Offline MultiMC is. Make sure that that's the one you're using

So there's no way I can submit my run without buying Minecraft?

yes there is

i mean, i think you are not spected to do so by general rules, as they don't accept what they consider as pirating the game but not saying it is 100% impossible to achieve

Oh, I got it. Thanks you guys for helping me.