No BJ auction experience, but I sold my Merlin-engined Rolls through Bonhams at Amelia a few years ago. Totally painless experience, very professional, negotiable fees and instant post-sale fund transfer, I'd use them again in a heartbeat.
If the previous owner had followed the service interval requirements you shouldn't need to do much. However, if you want to enjoy a couple of days of busted knuckles and frustration, change the fuel filter that will probably be frozen on, and be clean as a whistle when you finally get that...
I got 3 tickets last year, but in my defense the rental was an awesome three series M station wagon (sadly not sold in the US). Rental companies are so connected these days that it's an automatic debit.
Pulley and tune is probably the best single mod you can do to your GT: No downside and dirt cheap, think it cost me about a dollar per horsepower but that was 15 years ago. After that it starts costing money. I'm at 682rwhp (thanks Rich!) but it cost a lot more than $682!
"Cluch pedal to the floor scenario" is instantly fixed by installing a trannsaxle cooler. From memory, doesn't the manual say change all fluids every 30,000 miles?
Sixth time to Le Man's, always used a phone for navigation, never a problem (except in 2016 when Brian's phone took us to Lake Como Dry Cleaners instead of Lake Como!)