The example EULA contains text like:
> Failure to pay the Fee will result in the termination of this license. Upon termination, User must cease all use of the Software and remove it from all systems.
That directly contradicts what you're saying: that the software maybe use without payment, and only participation in the project (such as using the bug tracker) requires commercial users to pay a fee.
FOSS must not have anything resembling an EULA. Give me money or erase the software is just not free open source by any stretch of the imagination.
Everything recommended by the site is OK to do, and well within an author's right. What's wrong is the misinformation that the result is still open source.