The vents at the base of the windshield drain water into a structure called the cowl which conducts the water down both sides of the body behind the door hinge pillars and discharges it underneath. The cowl drains tend to clog with leaves and other debris. A wire coat hanger can be refashioned into a crude tool for raking out the debris.
The instrument cluster in these GM vehicles have stepper motors that control the gauges. It probably is the stepper motor for the fuel gauge going bad. This should have nothing to do with your hesitation, which could be anything from an O2 sensor to a good tune up.
Hi. Every car this days have immobilizer and key or phobe coded to it. If you replaced key but didnt switch guts to new same case you won't start up the car and you will have security codes pop. Usually service does such things. I don't think you guys can do it without equipment.
I would not think starter , maybe park neutral switch > It's a safety switch that won't let the vehicle start if in gear . If it doesn't start again try an put in into neutral an see if it starts . But to make sure starter is not bad do a starter circuit voltage drop test . Starter Voltage Drop
What grinds ? the starter ? if so it's not a key / ignition area problem . If the starter didn't do anything it could be a key / ignition switch problem . It's sounds like you really should take your vehicle to a qualified repair shop .