Previously I also sent a PM to theymos to change my username (more than 1 year ago) but until now he never replied to my PM and nothing has changed. I had reason to change my username, but it was never approved until now. I don't mind if theymos don't approve it for free although I still want it to this day.
So the bottom line is, OP, if you're even thinking about asking Theymos to let you change your username as a Newbie, forget about it. If it's something you really want to do, just create another account and start fresh.
Let alone account that are still rated newbie, there are many case of high ranking members also having to forget about it because theymos doesn't approve of it. The Pharmacist, you are the only one I know, after me.