I don't see why a choose of boot modes would be necessary. It's pretty easy to switch off wifi (literally, there's a physical switch on the LCD side). As for turning off the LCD, adjust the screen off to 30 seconds and then lock the screen. It takes far less time (<10 seconds) to do that then boot (~30 seconds).

Personally, I would find having to reboot it to be able to reactivate either the wifi or LCD to be much more trouble than the small convenience of not having to disable wifi and turnoff and lock the LCD.