I think it's a great idea to eat 14" walleyes and smaller is ok too. Old Salt thinks so too, he's just being Old Salt.

As far as the legality of a rock construction live well, I don't know. As far as conforming to the intent of the rules however there is really no difference between putting your fish in the well vs. putting them on a stringer. Bear in mind that they do become part of your possession limit the moment they go on a stringer or into a live well...even if they are eventually released.