I dont think it will hurt your sales at all. May actually help with some sales. I know several guys on the forums are in my favorite sellers list and if they put up an item I am after I usually send them a message asking if they want to do the deal off ebay to save fees. Several guys here have the same name on ebay as they have on the forum. James (our chicken shack) is the one I can think of most of the top of my head, and I actually met James through ebay prior to his posting a lot here (he was a member already just didnt post a lot).
I think the most important thing , at least when I am buying from ebay sellers, is their feedback. I do not tend to buy from sellers with low or no feedback count. I dont even usually look to see if they have changed their id recently, as long as their recent feedbacks are good.
Just out of curiosity, why not try to sell on the forums first? I dont know what you usually list so maybe it wont sell here but you could give it a shot.
I have caviar dreams and McDonald's pockets