I tried to mess with the GUIState ini´s in my swtor folder, but couldnt disable it. I also asked the CS, but as always they are completely clueless and incompetent:
Greetings,
I am Protocol Droid W5-A1 of Human-Cyborg Relations...
I have received your transmission regarding the in-game notification you are wanting to disable.
Unfortunately, We do not recommend members to edit .ini files located in the game's settings folder for this might cause the game to crash or give errors. However, if you choose to proceed and delete, maybe make some modifications, with these lines; GUI_NotificationCenterPositionX = , GUI_NotificationCenterPositionY = please make sure to create a backup copy of the file before making the changes. Likewise, it is also not possible to disable the "no target" notification anywhere within the in-game settings.
We apologize that we are not able to fulfill your request at this point in time. We will, however, be taking a note of your request and inquiry for these will help us improve the game in the future.
All of us here on the Star Wars: The Old Republic team would like to thank you for your support.
We are very lucky to have fans that share our enthusiasm for great games, and we hope to see you in-game.
Galactic Support is our specialty...
Sincerely,
Protocol Droid W5-A1 (aka Michael)