[12Ounce]

The fuel pump relay will not prevent the starter from cranking the engine.

The other items you mentioned, neutral switch (Transmission Digital Range Sensor ... I think) and the starter interrupt relay, are both good candidates. Unfortunately, there are other candidates ... loose/corroded connections, the starter motor, etc.

Do you have a multi-meter? If so, you can search and find what is "open".

Or, ... you can install a temporary jumper from the small terminal on the starter to somewhere safe near battery. When you get a "no crank", with tranny in Park and key "on'; push the jumper end onto the battery + post. I have such an (insulated) jumper permanently installed.... fastened to the small starter terminal on one end, the other bare end in a protective sleeve behind the battery.