bill85pi:
However, I'm not clear on what the digital pin numbers are. Would that be the ones marked as "Arduino Pin" numbers?
Correct, they are the ones in the blue ovals.
bill85pi:
Does this mean I can use either 4 or A6 for counter-clockwise orientation?
Use 4 for digitalWrite(), digitalRead(), analogWrite(), or any other usage of the pin that doesn't involve analog input. Use A6 for analogRead() or any other analog usage of the pin. It seems wrong to use the digital pin number for analogWrite() but that function name is not really correct. analogWrite() actually is PWM output on the pin, not analog, thus digital pin number is correct.
bill85pi:
Additionally, I'm still a little confused about the clockwise vs counter-clockwise capability. Since I was using the ATTinyCore "package" in Arduino, and the ATTinyCore option was selected by default, I thought this was the correct thing to use.
You can use either one, it's just a matter of preference unless you have a board with the pin numbers on the silkscreen or something like that. Arduino pins numbers are just arbitrary numbers assigned to the IO pins of the microcontroller because the concept of identifying the pins by port and bit is more complicated for beginners. The counterclockwise pin mapping used to be the only one that ATTinyCore had but a lot of people use the attiny core so the author added that option.
bill85pi:
it is a little confusing that they don't align with the ATTiny84 spec sheet.
The ATtiny84 spec sheet doesn't say anything about it. As I said, IO pin numbers are just an abstraction used by the Arduino core API. Atmel's way of identifying pins is by port and bit, for example PA6 is bit 6 of PORTA. There are physical pin numbers but those are not limited to IO pins and they will be different depending on the chip package so it makes no sense to base Arduino pin numbers on those. If you don't want to use Arduino pin numbers you don't have to but then you need to do direct port manipulation, you need to use Arduino pin numbers for digitalWrite(), etc.