With regards to transmission service...
my 07 went 780,000 miles without rebuild. I did all the servicing myself and all it consisted of was drop the pan and change the filters every 60,000 miles. Never flushed it.
Fast forward to my 16 and listening to some ‘experts’ I went against what worked for me previously and flushed at the first 60K miles and then filters and top up every second 60K miles.
I cant say for sure that this contributed to the demise of the transmission at juat past 210,000 miles but I’m not flushing it anymore.
I had other issues with it as well due to a failed internal cooler.
And for me I change the oil every 15K miles and the fuel filters every second oil change. I fuel at the same stops everytime.