Their Chapter name may be something along the lines of "The Lion Hearts" or "The Wardens of Dawn" or "The Silvered Guard" perhaps. (or just Grey Wardens)



They'd probably be descended from the Utramarines or from the Imperial Fists, or perhaps a bit of both. I'd lean towards them being both, as unlikely as that is.



As for the Codex Astartes, well, it's more like guidelines anyway. They probably say that they follow the Codex all the while finding ever possible loop hole they can.



"Am I too into this?" Don't you mean "Are we too into this?"



...does a bear sh!t in the woods?