Circuit Analysis Confusion
from what I can see, I would say your textbook is the Sedra&amp;Smith electronic book right?

You should check the chapter on MOSFETS(Chapter 5 in my edition), they demonstrate every possible configuration and the results.

Here is the resume table that they got on MOSFET



For the second point, you are wrong there isn't a short between Vo and Vicm actually, if you analyse correctly this problem you end with the CMRR of the pair
Regards MathieuL