How do I use Applescript with Keynote?
The following works for me:

set thisFile to "/Users/danielbeck/Downloads/test.key"
tell application "System Events"
    tell application "Keynote"
        activate
        open thisFile
    end tell
    tell process "Keynote"
        click menu item "Export…" of menu of menu bar item "File" of menu bar 1
    end tell
end tell


Changes:


activate makes the application frontmost, AFAICT.
GUI scripting requires the process of application "System Events", not the application of the same name.
You need to enter the actual ellipsis character … (Opt-; on International layout) instead of the HTML entity.