I read your guide, even linked it above and was precisely commenting on that.
This has nothing to do with selling.
LN has good (but not perfect, can by sibyled) privacy for spending. Your earnings still are not private, you are just putting on a shirt and walking with no pants.
I advise you to read/talk to ergoBTC or even Odell on the trade offs of coinjoin vs lighting regarding privacy. It's not that straightforward and shallow as your guides make it out to be.
If you are not open to honest constructive criticism, fine let's just agree to disagree.