The tank looks great, I love the holey rock.
The ID looks like a borleyi female.
I reckon the stocking number is fine at the moment - comes down to how much maintenance you are happy doing on it. e.g. when the strigatus, red empress, venustus, borleyi etc get big in a year or so, it may seem crowded then but fine when they are that size now. I keep large haps aswell and find that the bigger the fish, the more maintenance required and the more waste they produce, so when the fish get bigger I thin out the stocking a bit.