Sounds like you need to start going through things with a volt meter or test light.
Just to clarify, I think you said you hear a click when you turn the key to the ON position, but nothing when you turn further to the START position?
One of the first things I'd check is whether there is power at the starter, both on the main wire, and also at the solenoid control when the key is in the start position. That will tell you if power is making it to the starter and solenoid. If it is, then you found your problem, or at least narrowed it to the starter or solenoid.
From there I'd check the safety switches one at a time. Do you have a wiring diagram? I'm guessing the 3030 uses and ECU like my 5730, in which one wire on each sensor is power, and the other goes to the ECU. I'd check to be sure power is present at each switch, and that it energizes the lead to the ECO when the switch is closed. I know you tried shorting each switch, but did you check to see if there was power to each one?