I don't know if the Developer tools put extensions in anywhere, but I don't think so. In any case, you can remove the Developer directory by opening a terminal window and issuing the following command:
When prompted for a password, enter
your password. Assuming that you are an Admin user, it will begin removing the files and directories under the Developer tree. You might want to go for coffee (or your preferred poison); the deletion will take a few minutes - there are nearly 45,000 entries to remove.
Of course, the standard disclaimer applies here: I cannot be held responsible for any damage caused to the system by mis-typing (or not mis-typing) this command.
Please be careful. You have been warned. It worked for me, but as always, YMMV...
