Sure you should finish it after spending so much time on it.
I followed erinreid's tips and finally beat it. I just finished it
. the last level of res 5 is much easier than the 9th level.
Just as looseefur said. only server as much as you can handle. do not put in so many ppls, but you aint fast enough to server them. Max for me is 8 tables.
when possible, try to server some nack , it will gain more point so you can become an expert.
I finished most of the level in res 5 with expert