I think your fine, Im 6ft 2 and i've just bought a bigger/higher stem and it feels fine. Also your pretty good for about 2 months! I think all you need is better control on the back wheel then you'll be fine. But honestly you look fine and I would stick with mod for longer IMO.
Edit: I could see quite what stem you had but I use this one and its fine for someone my height
http://www.tartybikes.co.uk/product.php?pr...;category_id=29
Also look at Martin Grainger he is pretty tall and pretty good!