I wouldn't do the snail or the shrimp in the female sorority. The snail produces way too much bio-load which can lead to stressed out females. Also you want to have as many females as you can to spread out aggression so if you get rid of the snail you can get another female to make a nice number of 8.
And yes the Ghost shrimp will easily become a snack as it can't really defend itself. Sometimes some fish won't care about them but I've seen my girls at work and even though not all of them are super excited about eating shrimp, most of them are and they will kill of anything I put in that tank. They recently killed my bigger Nerite snail and this is all in a 33 gallon