I'm a wedding videographer. Some questions might be:
What style do they film in
What equipment do they have
How will they capture the audio (related to above)
Where will they be positioned in the church
How many cameras will be used
How long will it take to edit and compile
What happens if you want amends
If they pay for the wedding video music license
If you can choose your own music
If they offer highlights or any extras
Without seeing the company's basics there's a ton of other basics.
Out of interest, where's the wedding? We're Bristol based but cover the whole of the UK (have a wedding in Leicestershire this year) so if you wanted to look at some competition or an alternative then give me a shout!
Also if you could provide more details about the company in question or link me to their sample then I could give you some more feedback.