Water is pooling in the footwell, screen pillar, and other interior areas because the front drain on the driver's side sunroof is clogged. I've twisted, pulled, and pushed rather hard with some nylon fishtape—including with a pointed brass end—and a steel coiled drain cleaner, but thus far, no luck. According to how far the tape extends (it goes twice as far on the passenger side, which is not obstructed), the obstruction is towards the bottom of the screen pillar and refuses to move.
Additionally, I have checked the drains in the engine compartment and in the wheel wells and have found nothing clogging them.
I've also tried using a vacuum to blow and sucking. I have not yet used my air compressor for fear of rupturing one of the internal hoses.
No other options come to mind at the moment. I could use drain cleaner, but I'm concerned about the potential effects on metal, plastic, aluminum, and paint.