How can I safely leave my air compressor on at all times?
I think you are over engineering your solution. It is a small 1HP 4.1 CFM compressor with a small 2.5 G receiver and 90 PSI max operating pressure. The copper pipes will not burst in your lifetime. You may have a very unlikely  leak at the receiver valve  or a more likely leak in your hoses and connections. I leave my compressors on all the time and have copper pipe to all the outlets avoid pressurising lengthy rubber hoses. I also have a pressure gauge at each outlet. Bursting of pipes and fire hazards resulting from that, are so low I would not consider them. If there is a leak, the motor will run more than it should and you will find out from running noise or moving gauges. Your motor has overload protection in the very unlikely case it runs all day and you do not notice.  Establish if it has leaks by monitoring if you lose pressure overnight. Use soap water to find the leaks and eliminate them. My tanks retain pressure for several months without any leaks or the need for the motor to run when not used.