Is the black lead -ve and white lead +ve?

Good day/night, what is the useful life of the solar panel?

Tell please if it works with https://www.dfrobot.com/pro...

Could you use this panel with the Solar Power Manager 5V V1.1, despite the 100mA discrepancy in the Max Charge Current of the controller and the Operating Current of this panel?

What is the expected power I can get from this in full sun and indirect sunlight? Not max.

Is this panel water resistant?

Normally, yes. But we suggest you test with multimeter before using.