First of all we'd like to thank you for your preference and for the good mood
To connect a pushbutton to an analog port (e.g. A1) it should work by simply connecting VCC to one of button terminals and A1 to the other.
Regarding your questions:
a) Unlike when you're working with LEDs (where you need a current limiting resistor), for the button you shouldn't need any resistors
b) By default the digital ports are in a pull-up state... to connect a button to these channels you'll simply need to connect GND to one of the button terminals and Ix to the other (Ix being your digital input of choice; x=1,2,3,4)
c) VSS is a midpoint voltage (VCC/2) used as a reference for the signal conditioning circuit on sensors with a differential principle (± components)
d) We can send the diagram for the blocks of your interest; please contact us by e-mail to firstname.lastname@example.org
Do let us know how these suggestions work out for you, and if you need any additional support from our part, just let us know.
The BITalino Team