Thanks Mythic Moth Gaming for all your help! The session went really well - we had a mix of Mothership newbs and veterans and everybody had a great time. The immediate entry into the plush recreation lounge really sets the odd tone for the whole environment.
With the power off I had all 4 rooms unlocked initially which allowed for a slow tense investigation but did mean that when the power comes online nobody interacted with the door-lock-cycle. If I get a chance to run it again I would try it with one door unlocked initially.