Can this schematic protect my load cell/strain gauges from lightning?
Most likely your circuit will not provide a good protection, below is the better solution with trisil/transzorb/gdt. But even this won't protect your cell from destruction.



simulate this circuit &ndash; Schematic created using CircuitLab
The best protection you can have for a load cell, that supports a construction is an earthing strip, bolted between two construction ends.

Look here the copper strip mounted: