This is not an answer... just some broad scale advice... you need a lot of engineering that is not covered by the deposit you made, an electrical engineering firm would charge you $4,000 to $40,000 for this work depending on the detail required, probably more like $10,000
We can't do that for $25.
Summary of the issues:
The generator must be an industrial type, and rate for 3 or4 times the wattage of all the motors
put together... that will end up allowing you to run generator at 50% capacity needed for reliable long term operation and provide the 300% *higher amperage draw the motors require for the initial starting surge.
The generator needs to be 480 volts 3 phase to keep the wire size down.
If you want to harvest power from the load that is going down, that will need to be done with motors designed specifically for that purpose, and you will need need the electronics to go with it, and battery storage and an inverter
to make it happen.
That approach will most likely prove to cost more than it saves, and will reduce the overall system reliability.
Depending on what you have in mind there are easier ways to do this with existing counter weighted elevator technology.