This is hurting. You dont need to point your domains at each marketplace.
Afternic, just add it. No verification required
Dan, add it, you can even add names you dont own there.
Sedo, I always point nameservers to sedo, wait until it totally resolves
https://www.whatsmydns.net/#NS/
Then add the name. I have never had to add txt verification at sedo by waiting until ns propogate.
As for BIN, put bin everywhere, least of your worries is someone buying it at multiple places at once.
It doesn't matter where domain points to have your domains listed at 3 above marketplaces.
And by putting multiple NS like sedo and afternic on your domain at same time, it wont resolve.
txt verification is not needed at afternic, above information is incorrect.
Are you having an issue listing it at a certain marketplace?