Well, my show's over and things worked really well...
I did have one mid-show F*up. The Iphone spent half an hour in an actor's pocket during the show, when it came out it had been switched out of the webcam app. Oops! When I grabbed the camera from them, it had been switched to the stock iphone camera app, which caused me some confusion (maybe the actor tried to solve it by opening up the camera app?).
But I re-opened Mini WebCamera on the phone, and Isadora picked it up again instantly. Show goes on.
We hadn't really had this problem in run-throughs, but I had considered covering the iphone screen with something transparent that would block the touchpad. Didn't have time to figure it out (ulp!) and also thought blocking the touchscreen would just cause its own problems.
I need to create a flipover, velcro screen cover so I can have the camera running without touchpad vulnerable to touching, but actor can see the frame. Also really quick to rip open and do stuff on the iPhone.
Airplane mode works with Wifi on, connected to the macbook's hotspot. Gave the network a password so everybody in the room didn't hop onto the network and jam it up failing to check their email repeatedly, and also turned off internet sharing on the Macbook because when internet failed, Macbook shut off the wifi (you don't want that wifi network if you stopped sharing internet, right?). Losing the wifi while connected necessitated restarting isadora to reboot the Mini Webcam driver.
Also, the iphone seemed to be more troublesome when it wasn't charged right up to capacity. Left it plugged into a/c until the actor grabbed it 1/2 hour into the show.