various spellchecking/rewording

Some notes:

Reword the conditions on lines 43-44, and lines 63-64.

Explain where the value "7" comes from on line 97.

Explain the distribution attack. Why is it a problem that attackers can affect the distribution? What "direction" would they want to push the distribution in?

Explain the voting system: do hosts receives votes proportional the amount of files they store?

This paper talks almost entirely about files, not data. Are there protections against one host storing 10 10KB files, and another storing 10 10GB files?

I only edited up to around line 97. The rest of that section needs a good deal of clarification.