Not sure about the solicitor's letter thing - never heard anything like that but haven't even worked for BMed so maybe that's something unique to them. As for the ID80, you are correct in thinking it would be standby. Although your friend would be able to check the loads nothing is confirmed until the doors are closed and the aircraft starts moving. I have actually got as far as sitting on the aircraft when there was a problem with the loadsheet and 5 of us who were on standby had to be off loaded.
The other thing to remember is the an ID80 isn't always that cheap as you are paying 30% of the FULL economy fare - very few people ever pay the full fare in reality so you can often find a much better deal searching on the internet.
HTH Megan