The bombs are already loaded onto rockets, the idea is that when the Leader hits the button they'll get primed and fired when the priming sequence is ready. I realise now that I forgot to add a time they take - something like 10 minutes is probably good to give PCs enough time to defuse them.
The stairs are intended to go between the floors of the rig, with arrows poining upwards leading to the floor above (and vice versa with the stairs pointing down).
I hope you enjoy it if you end up running it!