In general, you can get away with this outfit, but things to consider.

Very few guys can pull off a bow tie in a non-formal event. Put it on, check your yourself in the mirror and then answer the question, "Do I look ruggedly handsom or like a geek?" Be honest (and it the tie is not one you have tied yourself the answer is already geek).

Second, it you wear a tie to the theater (any kind of tie) and it is not specifically for a gala event or possibly opening night, you will be one of the few. Not saying not to wear a tie. The last time I went to the theater (saw Spelling Bee - yeah Broadway Series), I wore a tie and a tweed Argyle jacket, but then I was at a pivate party in the corporate viewing box. On the other hand, I've seen both Rocky Horror and Urinetown on Broadway wearing a t-shirt and a Utilikilt. More typically, I an in a sweater or oxford shirt (no tie) and I usually fit right in with the non kilt wearing crowd.

Finally, not a big fan of the sweater vest (instantly take me back to 1982). If you really want to be dressed up, but avoid getting a kilt jacket of somekind at the moment the the advice of a vest given by others is your best bet (though keep checking e-bay, I have seen kilt jackets go for great prices).

adam