need a fix for controll arm aligment tabs

I"ve probed the area with a screwdriver and it seems solid, but I ordered bushings and bolts If i run into a issue ill fix it !!!
I own an mig and plasma cutter

Question ??? safe to weld on a car with gas in the tank/ electronic ignition?

Yes, safe, as long as you aren't welding the gas tank .
Disconnect battery ground cable to protect electronics.

Good luck .