Ubuntu – How do i completely uninstall tor? (and then install it?)

You've probably started Tor browser as root some time earlier. This has created files with owner root as you can see in the error output. Because you now run it as a different user, the files are not accessible/writeable by the user analytic4l and that's why it fails to start.

Fix this by changing ownership. Run in a terminal:

sudo chown -R analytic4l: /home/analytic4l/.tor-browser

OP posted:

I tried to manually start Tor (by typing /usr/sbin/tor in the terminal) and afterwards Vidalia and it works perfectly.

From the documentation of Vidalia:

I Can't Start Tor

The most likely reason that Vidalia could not start Tor is because Vidalia is looking for your Tor installation in the wrong directory. You can tell Vidalia where Tor is located by updating the Tor Executable option in the general configuration settings. Another possible reason that Tor cannot start is because there is already another Tor process running. Check your list of running process and stop the previous Tor process, if you find one. Then, try running Tor again.

If that did not help, check your message log to see if Tor printed any information about errors it encountered while trying to start.

Vidalia Can't Connect to Tor

Vidalia manages Tor by communicating with it via Tor's control port.

The most common reason that Vidalia cannot connect to Tor is because Tor started, but encountered an error and exited immediately. You should check your message log to see if Tor reported any errors while it started.

If Tor is listening on a different port than Vidalia expects, Vidalia will be unable to connect to Tor. You rarely need to change this setting, but if there is another service running on your machine that conflicts with Tor's control port, you will need to specify a different port. You can change this setting in Vidalia's advanced configuration settings.

Tor Exited Unexpectedly

If Tor exits immediately after trying to start, you most likely have another Tor process already running. Check the message log to see if any of the last few messages in the list are highlighted in yellow and contain a message similar to the following:

connection_create_listener(): Could not bind to 127.0.0.1:9050: Address already in use. 
Is Tor already running?

If you find an error message like the one above, you will need to stop the other Tor process before starting a new one with Vidalia. On Windows, you would need to look for tor.exe in your Task Manager. On most other operating systems, the ps command can help you find the other Tor process.

If Tor had been running successfully for awhile (that is, longer than a few seconds), then you should check the message log for information about any errors Tor experienced before it exited. Such errors will be highlighted in either red or yellow.