For me, roleplay is about expression of character. No one says he spends enough time being himself; I roleplay precisely to be someone else. Tarq is not I, and I am not he. I use an aspect of my personality for part of his character. Keith is far closer to the real me - he's me as I might have been, 17 years ago, in a parallel universe. I did not create Keith to confuse anyone. I created him partly because I wanted to investigate a certain alternate path I'd learned about in story mode, and once that was done I had fun fleshing out his personality. And though his story is similar to mine, he's not I, either.
That said, I've never understood two things about the way some people RP in MD (and other places around the web): roleplaying without reference to a system and roleplaying to the detriment of the setting. In any roleplaying game I've ever played, rules define reality and sharply constrain what a character can and cannot do. I once heard an MD player say, "It [RP] is like 'let's pretend' - anything can happen!" I strongly disagree. The 'anything can happen' approach to RP requires an implicit understanding between the players that they will respect each other's imaginings. I find that tedious. In a proper RPG, character actions (especially combat, 'powers', and skills) are maintained by the system, and therefore the system should be used. That is precisely why I find it odd and disappointing when MD players choose to ignore the combat engine and outer magic system almost completely in favor of their 'RP combat' and/or 'RP powers'.
When using the setting to define a character, you help expand that setting, but when you ignore the setting to make your character a robot samurai werewolf fairy, you undermine it. MD has a very rich (and rather thought-provoking) setting. If you are going to ignore it, you should at least ensure that you do not detract from it with your character concept's oddities. Tarq is an older guy who thinks he was a wizard in another world, but there's reason to think he's more than a little crazy - and the powers he does have all come from being a character in MD doing things in the world of MD. Keith is just an ordinary guy who, like some others, learned about the MD world and grew powerful from his interactions with it.
On a tangential note, I think it is just plain rude to ask game lore/systemic questions as an alt if you already know the answers to them. I can assure you from experience that such deceptions are not necessary for creating a character that the people who know your main account are not likely to recognize for quite a while.