P. 9.

Before you play the first note, place 1 on the G#, 3rd string, in preparation for the E7 chord. It will be there already for you when you get to the chord, and also guide your fingers in the run.
When doing the run from the open E Blues Scale, use 2 on the B, and hold it, lightly touching the 5th string after it plays, while you play the D and E. It will now be in place for the E7 chord.

An alternative to using 2 on the A7 chord. Using 3 is easier, but the properly developed hand can do both.  Relax that shoulder!

Again, keep 2 light on the B after playing, and use it to guide yourself into the B7. The other fingers should be close, relaxed, and ready to drop into the chord, or, you can even drop them lightly into place a few notes before.

P. 10 I do not advise using 4 on the 1st and 2nd string notes of Scale 1. At least, learn it with 3 as well. I always teach it with 3. The reason?

Because this is a prime bending note, and you will most often be using the 3rd finger to do this bend. In addition, all the licks a beginner should be learning use 3 on this note. It is very confusing for beginners to have to adjust to this after learning it with 4. In any case, using 4 is a skill that is developed with the Foundation Exercises from The Principles, and is vital for other styles, such as acoustic, but learn this scale with 3.

Trouble with Bars? Read "Easy Bar Chords"

P. 13
Many people have a hard time making the change to the D7 chord smoothly. Let's apply a little creative thinking: play the 5th fret note, C, with the index already extended into a 1/2 bar. Then, just slide it up for the D7 chord.

Do the same for the E7 chord that comes 5 measures later, play the 5th fret note, E, in a bar.