The seal under the timing cover is the oil pan gasket. For the crank seal you have to take off the timing cover to remove and press in the seal.
No you dont need to drop the oil pan, just the first four bolts on the oil pan that holds the TC. And be careful when you take out the TC because the oil pan gasket can rip, and this could be bad if you have the 1-peice gasket, then you would have to drop the pan or use RTV.