Kit,
I can fully understand your concern.
What I have seen so far doesn;t seem to be full-out aggression, but the spark of what could be fear and / or possession (probably the former) aggression.
She was a rescue from SPCA. I don't see her owners issuing any assertive commands (all sweet and encouraging - no firmness or reaction when I nearly got snapped when I tried to inspect her ears) and she goes anywhere / anytime she wants to in her house unless her owners tell her to get off the furniture. She's very responsive with 'sit', 'come' and 'off' (furniture) when needed. Treats training so far was what her owners were taught by the SPCA - command, dog follows, give a treat. With absolutely no offence to the owners, I am sure that they have been responsibly been doing what they were told to do when they adopted the dog.
I hope this helps. And yes, I would be open to a multi-page questionnaire.
