Ask Lemmygrad

That PSL is authoritarian, backed by a Chinese Maoist billionaire

That of course PSL would simp for DPRK because it’s authoritarian.

This part is just the usual reactionary tripe and not be taken seriously. Breaking it down:

• Authoritarian is a meaningless word: every state has a monopoly on violence in order to hold onto its state power (this does not inherently mean it promotes violence or seeks to abuse its citizens). Socialist states exercise power to suppress the capitalist power and transition to socialism and then to communism, and this is backed by a communist vanguard party. Capitalist states exercise power to suppress the working class more generally, but also consciously liberation-centered groups like those calling themselves socialist, communist, etc. (Takeaway: "Whose interests is power deriving from?" is a meaningful question. "Does power use violence to maintain itself?" is not)
• "Chinese Maoist billionaire": This is like a mad libs of red scare brain worms. The CPC itself, the vanguard party leadership of China, is not Maoist. They may at times refer back to Mao Zedong Thought, which is different from treating Mao's words as a whole brand of Marxist theory on its own. Though there have been Maoist groups historically, who took Mao's words more as dogma than "socialism with Chinese characteristics", they are about as far away from being a billionaire as you can get.
• "PSL would simp for DPRK because it’s authoritarian": I highly recommend Blowback podcast's season on Korea. It's not a pleasant history to learn about, but it may help in knowing more precisely why such a line is nonsense and why you can rebuff these people with confidence. Korea was brutalized first through Japanese occupation/colonialism and then through the US, the second of which continues this day with the occupation of what gets called "South Korea." Without the DPRK, Korea would probably be a colony of the US and China would probably be in a much weaker position globally. The damage that the US did to Korea, damage to civilians and infrastructure, is horrific. The idea of being called a "holocaust denier" for defending the DPRK is sort of like calling someone a holocaust denier for saying that the holocast was bad. It makes no fucking sense lol. If anyone was abused on a level resembling genocide involving Korea, it was the US doing it to Korea.

that PSL is riddled with sex abuse scandals

Don't know about reported incidents that have come up. It's possible they've had issues with sex pests, but the important part would be how they've handled it. Organizing, especially among people who can be as colonizer-brained as those raised in the US, is going to have problems sometimes. So far, I've not heard anything that would suggest PSL is fundamentally a problematic org, but local branches may vary, as can happen with orgs. As far as I can tell, they appear to be one of the most promising ones the US has in the current state of things, which is not a particularly high bar to meet given how mired the US left is in "reform", but it's something. It's also a reason why the imperialists would want to scare people away from getting involved with them.

Hope that helps.