In your first three points, you describe chemical reactions. What is it you want to know about them?
Apparently
Lawesson's reagent is p-Methoxyphenylthionophosphine sulphide dimer.
http://www.actim.com/enpll.htm
I was unable to find out more about the reagent. It's mentioned a lot on Google, but there's no site explaining what it does as far as I could tell. It's not in my o-chem textbook either.
Sorry I couldn't help you.