Ardunio Mega/ATmega2560: Using Port F or K for both analog inputs and digital outputs
On an ATmega2560, can ports have some pins used for analog inputs but others as digtial i/o? 


Yes, the ADC MUX controls the selection of the pin that is connected to the converter. This is independent of the digital pin control. 

Cheers!

PS: See the Arduino core source code for further details on the ADC MUX control registers.