I'd have to go and weigh my Littlest Stick to figure out just how much over the top you are with this. And it IS over the top. So the question is by how much.

You've made the nose much too long to balance with a Black Widow. The swept back wings means that it's even longer since the MAC of the wing is roughly at mid span and the CG will be around 1/3 back from the leading edge at that point. Combind that with a low weight for gear and model and you're going to need a LOT of tail weight for this one.

Basidally your wing should be mounted with the leading edge touching the back of the firewall I'd say. Or perhaps only a 1/2 inch behind it.