FRSO seems good on most things, but supports "upholding past treaties" with native Americans, which is somewhat of a red flag. PSL seems good but I've heard claims that they're not that good on the settler colonial issue either and lack proper democratic centralist structure. I don't know much about the WWP, but their 15 point programm doesn't mention landback at all. I know next to nothing about the other socialist parties/orgs on the US, so I can't give my opinion on them
I'll plug the IWW, I guess. Landback is a little out of scope, but we do try to address settler colonial issues, we've made some resolutions on that, and we have the Incarcerated Workers Organizing Committee which ends up doing a lot of work with empoc people (given the nature of the American prison system and all).
The IWW won't endorse lib politicians or campaign for them, which can be a concern for other socialist orgs. We have quite a few union shops, and even recently we've won actual material benefits for workers. And, of course, the IWW makes an explicit rejection of "a fair days wage for a fair days work", and calls for the abolition of the wage system (and capitalism).
The IWW doesn't have any issue with dual-carding or being a member of other socialist organizations (if I remember right, DSA doesn't allow PSL members, or something), it isn't trying to be a political party, but instead a labor union.
It's not without issues, of course, but those are mostly at the national level (and should hopefully be less of an issue next year). Major conduct violations (harassment, SA, etc.) pretty quickly lead to expulsion, but such violations aren't that frequent. There isn't screening to become a member, but joining an organizing unit (GMB, IU, etc.) generally requires an interview.