"Can possibly a very stiff throttle cause the actuator to pull enough current to fry these things?"
You can actually measure current draw to the actuator. Normal current draw will be between 120-180mA @ 13.8VDC.
Test the actuator spinning in both directions when measuring.
Operation should be smooth, not loud, not rattle, nor have current spikes while running.
1985 300SD - 'Grace' (198K mi.)
2010 Honda Fit Sport
2013 Honda Accord Sport
1996 Lexus LS400 (Retired)
1995 Ford Contour SE (Retired)
1976 Porsche 914 (Sold)
1972 Datsun 240Z (RIP)