HI there,
Lets discuss a few things.
#1, there are a few ways to determine the need for a fuel injection service or the need to add a bottle of Chevron Techron.
You can read your fuel trim tables, which is actually a quick way to determine the need. GM states +/- 8% is normal control module correction. I disagree as I have seen that level of compensation create issues with drivability. I prefer to see +/- 4% to be on the safe side. These corrections are assuming that you have a clean, uncontaminated 10% ethanol content fuel.
You can also ask that your dealership run an A.F.I.T. or an automated fuel injection test, using the GM special tool.
This is actually a MORE accurate way to determine the need, using complex flow calculations and balance average rates to determine if there is a flow balance issue or something else.
GM recommends Techron as a system maintenance additive every oil change or 5000 miles. Its a sound practice, even if you utilize TOP TIER fuels.
#2, Dexron 6, which is in your Corvette, is usually good for 100k mileage. However, remember, you are not correcting a distressed fluid condition. As every automatic transmission is used, particulates deposit themselves in the oil and thicken it over time. When you flush the system, you are actually removing the fluid and particulates. IT IS NOT THAT THE FLUID IS BREAKING DOWN! THAT would be the reason I would recommend you change your fluid, regardless of time at 50K.
#3, coolant is good for 5 years/100k based on OPTIMUM running conditions and correct electrical system integrity. TIME, regardless of mileage is used as all additives within coolant break down over time.
As for the rest, I would have checked the cabin filter, clean and adjusted the top, lubricated your rear toe links if you are Z51, lubricated all your latches and rear trunk lock cylinder, balanced your tires if they are over 1 year old and checked your wheel alignment.
Those would be my recommendations from a dealership technician.
Allthebest, Paul