I'm skeptical of both of those offers. You're spot-on about the bad grammar. Hell, I'd write someone off as unprofessional for even clunky writing in a professional email.
As far as the nature of the scams, I'm a bit paranoid, perhaps, but there are a lot of options for them. I'd be wary of embedded code in their guest entries that might do things you don't want, such as including a link that redirects readers to a fake log-in screen to steal user names/passwords. They may also feign technical difficulties to frustrate you into clicking a malicious link to "solve" their "technical difficulty." They could request your user name/password to post the entry themselves (I'm sure they dupe some people that way).
Overall, however, the red flag for me is that the money is flowing the wrong direction. They've done the work of writing the entry and you own the platform. You should be paying them. I'm sure there are exceptions to that arrangement, but this doesn't feel like one of them.
Posted using Partiko Android
Yes, very fair points, it doesn't really 'add up' does it!