So I finally have resolution...each member of our family was granted 5,000 points so 20,000 in total for the issues around seating and I was refunded the difference between the cost of the ticket at the counter vs what we were quoted when we needed to rebook my husband's return. The error was theirs - the ticket was never pushed through for issuance due to some kind of error (not sure if it was human or computer) - there is a difference between "booking a ticket" and the ticket actually being issued which is what matters at the end of the day. Also, there was an issue around the currency to be used and Q listened to the phone calls around the rebooking and my version won out based on the recordings.
So, am I happy? - I guess - or more accurately, I'm not angry...the mishandling of the seating and the change in return ticket for my husband was acknowledged and we were compensated. Would I have liked more compensation (in terms of points - yes, but I didn't really think they'd deliver). Also, I didn't feel like pushing on the fee we owed the car company when my husband was a no show due to being put on a different flight than his original rebooked ticket. I am very happy that the currency issue was resolved in our favor as that would have involved a lot of money had it not and I KNEW what I had (or more accurately, had not) been told when changing the return leg. Also, the customer service rep who handled this matter was very good at keeping me apprised (they needed to do a lot of internal investigating) and also acknowledged how long my phone calls with agents were as she had to listen to a few of them.
Lessons learned - keep notes of who you spoke to (first name and location of rep), time of your calls and phone number you are calling from - this helps them easily find the recordings. The recordings are only kept for x weeks (I think 6) so act promptly if it is going to come down to what was said on one of the phone calls. If you have a messy booking because of changes, check & recheck again and again. I should have confirmed my husband's ticket at the Qantas counter in the lounge although frankly, it still surprises me that it fell through the cracks and was never reissued - I'm also not so sure much could have been achieved in the 40 minutes we had at the lounge other than knowing that the ticket was a mess and not booked.
Thanks for the support on this forum! happy travels.