Ahh I love this, a totally unique twist - you can't beat a good reptilian overlord! The idea that the option is purely for show is a great touch, to keep their little people hive ticking over. My mum always used to say, give people a choice and they will agree to all sorts of things (she mainly used that to get us to do things like put our seat belt on - do you want to do it or should I do it for you?) I also enjoy how closely monitored the little regime is, she didn't even need to deliver the form for them to come for her. The people disappearing under questionable circumstances is a good device to explain the human disconnect. A very enjoyable ending!
It just seemed to me like that is where the story was headed to where I took it when you wrote about the place being sealed because of something happening x amount of years ago. Reminds me of a movie I can't name right now.
I'll have to remember your mother's saying.