Answer:
It's to support subject/verb inversion (as in "neither do I" or "so do we"). So 'does' is standing in for the main verb, 'discover' because modern English avoids inverting except with auxiliary verbs such as do, can, will. Without 'does', you'd have to say 'Only by ... views of others DISCOVERS ONE ...' which isn't done in modern English.
I would say that they shouldn't be surrounded by a lot of white space and should have clear captions. The question of white space is one of good presentation so the visual looks like an integral part of the whole topic and having clear captions is so that the visual is well explained what it is.
The correct answer is C. Read the lines out loud. The author suggested several strategies for "Reading Shakespeare". One of them is "try reading out loud". Doing that you can get a sense of the rhythm of the lines from reading them loud that you cannot get from silent reading.