The reason for the oil fill level is to prevent the pickup tube sucking air and frothing under spirited driving/acceleration. If the oil is on the lower side its possible for this to happen where you get dips in oil pressure at the very wrong times when its needed the most. Fenfab makes a aftermarket oil pan with extra capacity and baffles that pretty much solves that problem. Otherwise keep an eye on your oil level , keep it always on the high side.
Never heard of trans fluid changed with a tune. I can say from the research of reading forums and watching vids on this vehicle, better to change the fluid on the early side like 25K miles especially if you enjoy getting on it or with a tune. The transmission is hard on the fluid it seems. I upgraded to the PPE aluminum transmission pan early and whatever fluid that came out I replaced with Amsoil ULV. That was like 5K miles and I plan on doing another dump and fill at 30K miles. Also never have a shop do a power flush with the machine on these transmissions. I don't know why but many folks in the know here recommend against it.