Using AppleScript to open an application without the app stealing focus

Question

I use iA Writer enough that I would like it to open in fullscreen on login, but unfortunately the developers have disdain for preferences.

I decided to write an AppleScript that I could add to the startup list, but I can't get it to work properly. I'd like to open a specific file using iA Writer on login, in 10.8 fullscreen mode, but without changing focus from my normal desktop, or a least automatically returning me to my primary desktop after launch. EDIT: Here is my code after suggested edits:

set front_application to front window
tell (application "iA Writer") to open (POSIX file "/PATH/TO/FILE.txt")
activate application "iA Writer"
#EDITED# tell application "System Events" to keystroke "f" using {command down, control down}
#ADDED# delay 1
#ADDED# tell application "System Events" to keystroke "1" using control down
end tell
activate front_application

This code successfully opens the file with iA Writer in fullscreen, but switches to the new, iA Writer-controlled desktop, waits a moment, and switches back to my main desktop.

Since OS X's change from spaces to desktops, I don't even know if it is even possible to open an application in Mountain/Lion fullscreen without it stealing focus and forcing a desktop switch.

Many thanks to @Lauri Ranta for your help thus far!

Any further help, regarding keeping iA Writer from switching desktops when becoming fullscreen, would be very appreciated. Thanks!

Answer 1

(I removed the original script, but I couldn't come up with anything better than this either.)

set fw to front window
do shell script "open ~/Notes/todo.txt -Fa iA\\ Writer"
delay 0.1
tell application "System Events" to tell process "iA Writer"
    perform action "AXPress" of (button 1 where subrole is "AXFullScreenButton") of window 1
end tell
delay 1.5
activate fw

WriteRoom has an option to open documents in custom full screen windows. If it's selected, you could use something like open file.txt -Fjga WriteRoom.

If someone else just needs to open an application on the background, you can use open -jg or launch. launch sometimes opens a visible window if an application isn't open and open -jg if an application is open but has no windows.

set b to "com.apple.TextEdit"
tell application "System Events"
    if bundle identifier of processes contains b then
        launch application id b
    else
        do shell script "open -jgb " & b
    end if
end tell