Here are a few initial questions to ask the sellers.
How old is the roof?
Do you get water in the basement?
Is there an oil tank on the property?
When was the last time the boiler or furnace was serviced?
why ae you selling the property?
Has there ever been a fire?
What are the neighbors like?
Is there a sepric system or a well?
What do you like best about the home?
These are some important questions to ask. These allow you to obtain more information and also allow you to get an initial impression of the sellers.