No problem, 4 yellow tangs may be pretty unnecessary in my opinion as well. That is a high bio-load fish and having 4 will put a lot of strain on a 180 with all the other fish going in as well. The 4 clowns would more than likely fight. You should stick with a pair. The other fish and inverts look good to me. A fish list like this that is based on your list would work well.
Pair of clowns
The 3 of pairs clown gobies (yellow, black, green) The black and green will be tough to find in a 180 though!
Zebra Barred Dartfish
1 Yellow Tang
Maybe another species of tang like a Kole or a sailfin
The shrimp/goby pairs
A group of Chromis
That would be an alright bio-load and provide lots of color and interesting behavior. Also, if you are getting a bubble tip anemone there is no guarantee that the occ. clowns will be hosted. A pair of Clarkii clowns are naturally hosted by bubble tips and much more likely to develop a symbiotic relationship with the anemone. They do get bigger than the occs but they'd be fine in a 180. Just my 2 cents.