I am a bit confused on the rules here.

And I've copied the rules just to make sure (you) can review them and discuss....

The second rule - allowing a commercial link seems to be taboo, since the first rule - no links at all - should override it.

Unless it actually means
"You can insert a link into your blog if you are recommending someone, and provided you are not making any financial returns/benefits from giving that review/compliment"...