Performance Issues: General Suggestions and "Gotchas" ???

I have written a Photoshop CS5 Extension in ActionScript. "Its performance is too slow", says the man in the corner office...

I would appreciate suggestions both for what I SHOULD do to speed things up, and also what I should NOT do in order to speed things up.

The general purpose of the script is to open a few images, and place them and their clipping paths (PathItem objects) at a given location on a single target page.

My general workflow is:

<pseudocode>

Create target document

BEGIN foreach image to be copied onto the target document:

     Open image document for image

     Scale image document to match the DPI of the target document

     Copy/paste from the image document to a new layer on the target document

     Move the new layer to its desired lation via transform()

     Convert the clipping path (PathItem) data from the image document to an array and add it to a aggrregateclipping path (PathItem) - a union of all clipping paths

     Close the image document

END foreach

Create a new PathItem in the target document from the aggregate clipping path

Flatten target document

</pseudocode>

What could I do to improve this? For example, I assume that the History functinality consumes resources. Could I turn off history? Any other ideas what I could do or not do to improve performance?

TIA,

mlavie