One thought on chain
I would stay with 5/16 for everything and if concerned about working load upgrade the 5/16 to High Tensile / G4 chain. This will give you greater working load than standard 3/8 with lower weight and takes up less space. I personally would not stay BBB unless you have to as standard chain has better working loads for the size.
With regards to
anchors there is no right answer but your
CQR is plenty for the boat and if looking for options the only other one not mentioned I would look at is a Spade.
Jon D