How necessary is a Hotel Reservation for a Tourist visa?

My son is currently living in Shenyang and there on a tourist L. He wants me to visit him Aug 20 -Sept 10. He will meet me in Beijing when I arrive there Aug. 21. I have round-trip tickets from Portland, OR to San Jose to Beijing for those dates. He will be making in-China tour arrangements for the both of us. He speaks Mandarin. I'm not exactly sure of the various tourist city attractions, so I don't have a detailed list of those, nor do I have hotel reservations. I want to file an application with the Chinese embassy in San Francisco and pick up my visa on June 18. Can I use the embassy forms for application. Can I submit a scan of an emailed letter from my son inviting me to visit him for his signature? Thank you P.L.N.