This was an interesting read.
I'd like to add my input:
This type of roleplay is supposed to simulate - as much as possible - what one could do in real life right? So, whatever you roleplay should be realistic as possible.
So looking at this in a real life situation. (And for example's sake, you're character is named Bob.)
If you've never met, say, John from Greece then of course he'd be none the wiser to the identity of your character. However, if you met him again, he'd recognise you, as whatever name you told him, before you even spoke because he'd recognise you.
If you meet someone in real life and they know you as bob, and then don't see them for 2 months, they'd still remember you, no matter what you choose to call yourself or what accent you take on.
It's a good idea and I wouldn't want you to put limitations on how you roleplay so I would suggest a totally new outfit and a mask with glasses, maybe it would be reasonable. Anything is possible in games I guess.