Good to hear that the plugs are dry; that is consistent with lack of fuel, both supply and metering. Small diam. center electrode probably = Bosch Platinum. The sensor plate is not mechanically connected to the throttle plate; it is moved by air flow. If the safety switch is mis-adjusted, too much sensor plate movement will be required to open it than is produced by a low idle. The test is to unplug the safety switch, and then start the engine. That will ensure that the pump runs after the key is released from the start position. Re: lack of throttle response. Assuming that the throttle linkage is intact, if the pump is not running after the key is released, the fuel pressure (from the accumulator) will be too low to pick up the engine. That also suggests that the aux air valve is open.

There is a connecter block on the right wheelhouse where the leads to/from the starter motor join. One of them (about 16 ga.) when jumped to +12v will engage the starter.

Control pressure regulator = warm up regulator