Peter...I'll try to answer your 4:05 pm question, but the brain's not working real good as I'm recovering from the flu and doing this sans instrument.

The mixolydian modes over the changes you suggest will work some of the time. It'll sound much more like jazz than blues to many blues fans, though I don't think the distinction is important. Whether jazz or blues or some hybrid, some notes will fit all the time, some only some of the time.

Or look at it this way. The 3 modes you ask about using only differ by a couple of notes. In this context you've got CDEFGABb over I7, FGABbCDEb over IV7, GABCDEF over V7. The C minor pentatonic is CEbFGBb. Add the "blue note" Gb/F# for the C blues scale. The beauty and therefor appeal of the blues scale is it works over the I IV V chord changes. The downside is that it gets a little repetitive to some ears and hands. Add those other mixolydian mode notes where they sound good and it gets more interesting.

But...I've always thought that the guiding force here isn't so much the scales as the dominant seven chords which give us (in this case) the notes Bb, Eb, F, which with the tonic and dominant major intervals C and G (common to the 3 modes you're using) make up the pentatonic. (The raised 4th blue note can act as a passing note between its neighbours or a note of "suspense".) At any rate, notice that the notes Bb, Eb, F, are the 7ths which define the switch to each mode over each chord change in your example. They're easy to find, two frets (whole step) lower than the chord root.

Hope this helps.

Peace, Mooh.