hi spacemonkey
used to live in ny and have made fairly regular visits back since. just a few comments.
empire state - excellent idea, think about going after dark (the night time views are my favourites)
boat trip round the island - these trips can be expensive, you could try taking the staten island ferry and/or walking across brooklyn bridge and back instead, i would recommend these anyway.
helicopter ride - yes, yes do it! again think about a night time trip.
broadway show - cut price broadway tickets at the "TKTS" booth in times square, they usually have a good range of shows.
drag show - er, pass!
shopping - soho, many designers but now largely taken over by the chains. designer boutiques on the lower east side and in tribeca. department stores - macys, bloomingdales, and a whole gamut of big stores on 5th ave between 42nd and 59th (barneys, tiffanys, etc, etc)
other things:
ellis island - if it's open.
metropolitan museum of art - it's fantastic
guggenheim museum
museum of modern art
walking tours by the big onion (they are all graduate students from columbia, the quality is extremely high), walks cover all areas of manhattan and are listed in Time Out New York - see below
exploring the village
having a (very expensive) drink at the rainbow room (top of the rockefeller centre)
walking around the reservoir in central park
gospel brunch in harlem
having a drink in one of the really, really hip hotel bars, e.g. The Mercer.
Two great resources, used by the locals (you will find restaurants, bars, shopping, theatre etc etc - and yes probably drag shows!)
CitySearch NY , and TimeOut New York - suggest you pick up a copy of this as soon as you arrive.
hth, have a wonderful time - i'm jealous!