Thanks for all the responses guys. I forgot that Project Red has all those fancy programming blocks. That will probably be the easiest way to do it. The wires are so easy to run, but I've never really done much with vanilla redstone and I just get totally lost trying to understand how it works. In particular, I can't understand how to connect pressure pads on the floor to redstone underneath. No matter where I try to put it, it doesn't seem to work. It just stays in my hand, won't let me put it on the blocks. I can only put it on blocks which are too far away to connect to the pressure plates.
In any case, Project Red should save me here. I'll give it a try and if it works, you'll know when my next video comes out (hopefully this weekend).
I'm having another glitch as well, though. Maybe you guys will be able to help. I have a load of mods installed. One of them is Thaumcraft, and another is Wild Caves, both of which cause special plants to spawn (the blaze powder flowers and quicksilver flowers, the glowing underground plants). They all appear normally in my game, but when I mouse over them, they vanish. I can't harvest them. They just disappear. I figured there was probably some kind of conflict between some of the mods I have installed, and decided to just let it go, since I don't desperately need either of those things. But just this past weekend, I got my mom to install the same pack of mods I'm using. She has all the same ones as me, with all the configuration files the same, but when we played together, the plants glitched for me but not for her. She was able to harvest quicksilver, no problem. Also, when we found a greatwood tree, when I looked at the leaves, they turned into silverwood leaves for me. This didn't happen when she looked at them. They were fine for her. (This doesn't happen when I play single player; it only happened when we did LAN play, with her as the host.)
So obviously there's something wrong with my installation which isn't wrong with hers. Any idea what kind of errors would cause this to happen? I suppose I can try making a fresh installation with the exact files I sent my mom, and see what happens (and try to transfer my saved world over), but I'm just scratching my head trying to figure out what's going on.