The Doctor rightly ascertains 'the truth' about Oswin due to the fact that she would not be able to get hold of the milk for all the souffles she claims to have been making for a year. But there are other perishable ingredients used to make souffles: cheese for example (if the souffles are savoury) and (just as important as milk) eggs. Oswin could have used dried egg but for that matter she could have used powdered or UHT milk. The Doctor should have asked about the eggs as well.
About 17 minutes into the show 'Rory' wakes up in a room full of Daleks that are not moving, he goes up to one It has two lights on its dome but in the reverse shot from behind the Dalek (& from above) the light on the left hand side of the dome is missing, there is just a hole in the dome where the light should be. The shot changes six times so it is very noticeable.
When Amy and Rory are taken by the Daleks they are placed in a room with a rising floor. Later when the Dalek ship arrives at the Asylum the floor opens up again but the walls to the room have disappeared.