Imagine being a one person "company" that puts stuff on DMSGUILD! Even if I have a person or two read things, no chance I can do all this, no chance I realize all the things are blindspots for me. It kind of scares me, actually....
It is scary, but there is stuff you can do.
First off, just avoid anything relatively obviously risky, and like basic self-awareness should be helpful here. I think one of the issues a lot of nerds online (and I use nerds with love here) have is a feeling that, if they like something, it
must inherently be fine, at worst it's a matter of finding the right excuse (you see this a ton with fans of problematic anime particularly), and if you can at least dispel that illusion, you're in a much better place. Don't give yourself excuses like "it's realistic", particularly, that's an incredible get-out that leads people into deeply murky waters*.
I feel like the "I like it so it must be fine!" probably applied re: Hadozee. Like, oh they're cheery and fun, so how could they possibly be bad right? Oh dear. Never assume because something is cheery/fun to you it's going to automatically be fine.
Second off, I kind of hate to say this, but most people who have problems in this regard tend to be serial offenders, that doesn't mean if you've never had a problem you never will, but unless you were only going out to a narrow, friendly audience, it's less likely. And if you listen when people say "Whoa that's problematic!" rather than dismissing people, well, you're probably going to find weakspots quickly (I'm not suggesting you wouldn't listen - but a lot of people refuse to - including some fairly serious professionals, particularly those who regard themselves as artistes really emphasizing that e).
Thirdly, as others have said, you can find people willing to do this stuff for cheap/free.
* = I think it's okay to use that within reason when writing fiction, so long you understand what you're doing, but D&D adventures designed for mass-sale and
intended to be relatively unproblematic are very different to fiction, which can be challenging intentionally.
I have limited 2nd hand experience with sensitivity readers but all good to great... but i can't help but think of star trek voyager not any of those good examples when I hear this... mostly because I have little faith in wotc hiring the right people
Wait did VOY have sensitivity readers? Surely not? It has some of the most repeated racist and weird racial stereotyping (of humans, particularly but not limited to Chakotay). Paris straight-up racists Chakotay in like the second episode. I know because I watched it a couple of years ago and I was like "Paris what the hell did you just say?!". Also let's not even get started on Neelix and his underage girlfriend because goodamn that should have caused arrests and ransacking of computers (not of the actors, but whatever writer came up with all that) lol not just sensitivity stuff.