Not Impressed

With regard to your branding. You offer a free plugin on ww.wp.xz.cn repository. You require a service (which is, unfortunately, allowed). But when someone tries to disable your branding (which is supposed to default to off) you require a paid membership.

There are a few tutorial plugins available for free, why would we want to use one that requires connecting to your site in order for it to work?

I suggest you make your free plugin fully functional without connecting to your site. If you want to market a paid version, then do so. But it really isn’t necessary to require such a connection to create tutorials.