Hi Sarah,
Be very cautious. I think the questions you are asking the supplier about references from brides, to look at pictures from a whole wedding and a contract are all very valid and pretty basic.
It's not only the price that matters. I am sure anybody that owns a camera can trigger the shutter and charge less than the actual market price for a professional wedding photographer. But to go from that to being a reliable wedding photographer able to provide you with a beautiful set of your memories...that is a long way to go!
You still have about 9 months to your wedding. What I would do is take my time. Go through the threads of PV wedding photographers to explore your options, get in contact with the three that you like the most within your price range and then go from there.
There are even some threads in the forum that have a compilation of PV photographers. It should take you not more than a week to figure it out. One week for 8 months of peace of mind.
I guess my whole point is that your questions are totally valid and the photographer you will trust with the memories of your lifetime should be able to answer them positively.
Best wishes!