In your Everquest II folder there should be a file named EQ2.ini. Edit that file and add a line that says this:
| Code:: |
cl_show_welcome_screen_on_startup 0 |
That "should" turn it off. Should work for any UI, not just Fetish. Haven't tried it myself but for some reason with Fetish, once I closed it the first time, it hasn't come back up. Maybe I'm just lucky.