That's a fairly large turbo for an A12. It probably wont make good power until over 5K. It should make plenty after that!

How much total ignition timing has it got?

Its very important to make sure the regulator is doing what it should. Basically starting out at 3-5 Psi and then having it referenced to the inlet manifold to ensure the base 3-5Psi is always maintained above boost pressure.

Unfortunately, It will be nearly impossible to tune without the aid of a dyno. Fueling can be corrected on the road if you have access to a wideband air/fuel ratio meter, but monitoring fuel pressure at the same time will be very hard. It will be a very slow and tedious exercise aswell.
Ignition timing will be impossible to get right on the road. If this is too advanced, it will cost you an engine very quickly.

As far as it not making boost...I'd be checking for leaks. Ensure the blow off valve(if fitted)is plumbed properly and sealing. Check all clamps, hoses and flanges are air tight. On the Exhaust side, check manifold flange(to head) and turbine inlet flange. Also check that the waste gate actuator rod isn't binding, and the flap is being held shut with a little pre load(a couple of mm) of the actuator rod.

I'll keep thinking, and if something else comes to mind i'll let you know.