#1
On Page 14 in the top right right corner is a "C Scale Form." When he says to "Play through each [of the scales] one string at a time, is this what he means?

--------------------------------------------------------1----4-----------
---------------------------------------------2----4-------------------
--------------------------------1-----3----------------------------------
---------------------1---3-----------------------------------------
----------1----4--------------------------------------------------------
1---4------------------------------------------------------------------

If so, then why does this sound so unfamiliar? It seems random. Unless there's something to it down the road. Or am I not understanding something?
#3
I can't say I'm 100% sure, because his wording is kind of vague, but I think he's saying practice each form by starting on the 6th string and play the two notes, then move to 5th string, etc until you ascend from the lowest note to the highest, then descend back to the lowest note. Do this for each form.

Another idea is to learn the scale on each string, or in string pairs (6th & 5th, etc). Although the book is based around the CAGED system designed to use patterns I'd advise you to also learn the notes, how the scale is constructed and the intervals used. Knowing that information will help you down the road.

It probably seems random to you because you haven't trained your ear yet to recognize the scale. Keep in mind if you are using this as a major pentatonic, the tonic is on the 5th string (4th finger) and if you are using it as a minor pentatonic, the tonic is on the 5th string (1st finger). Begin the scale there to hear it better.