As said you have, snapped either (C) Compressor outlet or (W) which goes to actuator, off the amal valve it's actually a solenoid, if only happening at high revs you are experiencing overboost protection as actuator cannot open wastegate but should drive fine off boost.

As for starting, the rotor arm should face number 1 on cap when engine is at TDC there is a pinhole in the dizzy which will be at this point as well.

Martin