Nazana makes sense to me. She's not quite good enough to be used in endgame - for one thing, her decrease attack can't reach a 100 percent chance even when booked - but she's solid and you could use a tanky champion as second 6*. 

You'll also want to 6* all of the champions you intend to use medium/long term on the CB, so that includes Coffin Smasher. That's important not only for increased survivability, but also because it allows them to get the Warmaster / Giantslayer masteries, which will dramatically increase their damage per CB run (as well as their damage on the dragon or other dungeon bosses). 

You might have some 'hidden gems' in the rest of your roster, there are a number of rares who are really good overall (Coldheart, Apothecary, Reliquary Tender,...) or at least have some rare skills that make them worth building for certain content. 

Thanks man!  Sounds  like  solid  advise.  I  have  been  on  the  look  out  for  the  characters  you  mentioned  as  they  will  help  round  out  my  team.  In  the  mean  time  will  keep  working  on  what  I  have  as  you  suggested!