Dropping the pan is good. You might see something laying at the bottom for an early warning. You should also change the filter at every ATF+ 4 change. Use ATF+4 only.
Depending on what vehicle you have, there may be TCM software updates available to enhance shift quality and transaxle longevity.
Since there is no supplied dipstick, you will want to get one if you don't already have one.
There is no OEM reusable pan gasket and I can't vouch for the available aftermarket ones.