Grammar Help

1. Edward Jones wrote the essay, "Shacks." He was in his first year of college. (Or, Edward Jones wrote the essay "Shacks" when he was in his first year etc...)
2. Having a passion for writing, the letters Jones wrote every day were a way he could cope with loneliness. (I see nothing wrong with this sentence.)
3. The short essay was written in 2011. It was about Jones' first experiences in college. (Or, you could substitute a semicolon [;] for the period, retain the lower-case 'i' and keep it in one sentence. Your choice.)
4. Jones had always been interested in writing and was good at it. His letters revealed that skill.
5. His letters were long and detailed even though he did not live in a computer environment. (That's the reverse of a run-on sentence.)

It was not the letters which had the passion, it was Jones.

Since he had a passion for writing......

I see. Misplaced modifier. Still, it's colloquially quite correct.

I would rather say "acceptable, if sloppy" in conversation, and definitely careless in any written work intended for serious consideration.