Never sign away all rights. Never give exclusivity without a time period (and even then I often push for an exemption for "Best of" anthologies and award anthologies, which any good editor will give because they are good marketing for the publication).

Never give rights to somebody who doesn't have a plan to exercise them. For example, don't give audio rights unless the publication routinely podcasts stories.

No sim subs is completely normal in fiction, though. It's still very rare to allow them, and understandably so from the perspective of the editor. I don't consider it a red flag...or I'd barely have any markets to submit to. But it's something to plan for, and also I don't submit to non paying markets unless it's for a charity I want to support.