Point 5 is very interesting. With all kinds of eReaders out there, I think this is becoming more important for a writer to consider. Sometimes I’ll read a novel on my phone, sometimes on my computer, and large paragraphs do get tedious the smaller the reading device gets.
One thing I would add is when submitting to an agent or a publisher, follow their guidelines exactly. My publisher likes ellipses to be 3 periods with no spacing between the words or end quote. “I’ve been think…” not “I’ve been thinking… ”