Overall, it sounds pretty well thought out. I'm guessing the single plane intake was more for the nitrous than torque off the spray, because that's costing you some torque down low.
The timing can be as high as the engine likes it as long as you keep it from detonating, of course. I always try to use an advance curve (initial plus mechanical). That always seems to work better on the street, unless the cam is just too radical. But my first impression is that the cam isn't too big to use a curve. But it would be a short curve, the mechanical advance might end up being less than 10 degrees, and that's close to the point where locking it full is a viable option. I would let the way it runs locked at full timing be the deciding factor.
I also like to use a vacuum advance, even though this flies in the face of tradition according to some. When using a lot of initial or locked timing it needs to be connected to ported vacuum. It also needs to be adjusted to give about 10 degrees advance at a high enough vacuum level that it doesn't cause any detonation when the engine is under any real load.
When using nitrous, the timing has to be retarded from max naturally aspirated power timing. This is best done w/an ignition box like the MSD 7531 or something similar. That way you can run max timing under all conditions.
If it gets hard to start you can use an ignition interrupter that lets you spin the engine over w/the starter first, THEN when you let go of the switch the ignition is hot. That prevents the starter from kicking back.
You already know the gears are hurting you. What kind of weight are we talking about here? If you are using an automatic trans, the stall speed needs to be at least
3500 rpm and a higher stall will accelerate better.
Do you know the actual (not theoretical) compression ratio?
This is just the tip of the iceberg. Others here will likely chime in and I will give this whole thing some more thought and get back to you.