Alice is a big "licker" too, she's on my lap right now licking the harm of my computer chair
. She licks her front paws, my leg - I asked my vet and he said (after checking her paws for any problems) it's just a habit and to distract her.
Now my Beagle, she sounds more like your dog, lickes whatever she's laying on (couch, blanket) and also does the "air licking" thing. She also does something called "flank sucking" where she sort of sucks/chews on her hind thigh. I asked the vet I used to work for and he researched it for me - it's just a habit that is caused by bordem or sometimes stress, but Alice doesn't seem to be in any stress at all when she does it (most of the time my Beagle doesn't either, although the flank sucking I notice when she's stress for some reason) . It almost seems to me that it's relaxing to them?
I always just figured my Beagle licked "the air" because her sense of smell is so strong that she "tastes" what she smells in the air???? I'll be interested to see what other responces you get