I drove the Camaro extensively before I bought my 18 GT. I just preferred the way the Mustang drove. I also liked the interior more. I also didn't like visibility out of the Camaro.
That hood would look killer if you painted and striped it to match.
I think in the rpm band you will be running on a road course, you won't have an issue with those 62s spooling or keeping you in the power band.
I believe it's this kit that is from CJ Pony Parts. https://www.cjponyparts.com/magnaflow-cat-back-quad-tip-exhaust-kit-competition-series-3-stainless-steel-premium-fastback-gt-2015-2017-no-active-exhaust-fastback-gt-2018-2020/p/CBG88/
I only paid slightly more than that for my 17 that was perfect with 2K miles on it. There would be no way I would pay 45K for a rebuilt title car regardless of year.
What can you get through your bank, or a credit union? Compare that to what the dealership offers, and if they won't match the interest rate, just use the lowest one.
Blue smoke is definitely oil burning. Car should not have been CPO if it had a tune on it when they took it in. The tune should have voided the warranty.
I bought my '17 in February. I was looking for lightning blue, and found one on a BMW dealer's used lot. Picked it up with 2,092 miles for mid 40K. I've been looking at prices since then, and thinking I got a pretty good deal rather than waiting...