I'm not a diagnostic expert but logic would tell you no way 3 out of 4 doors would have wire failures all at the same time. Neither would the actuators of 3 out of 4 doors all fail at the same time.
You mentioned the most logical explanation already and that's the master switch in the driver door.
There's a guy in Washington state that parts out 4runners and his prices are fair. Maybe he has one he could sell you so you're not forced to buy a new one.
The name of the guy is Josh Young and the name of his business is PNW 4Runner Connection. Message him on Facebook and tell him what you need. He usually can get back to you very quickly, usually within one day.
PNW 4Runner Connection - ?? Tell Josh Timmy the Toolman referred you.
For the window tinting, do they actually remove the glass from the doors? How would they get water inside the doors? That's not making sense to me. Were they working outside on a rainy day?