Answer for REIT Stocks

Due to REIT mainly earns rental income from commercial properties, the income generated should be more stable than income earned from businesses, generally. There are exceptions though, as not all REITs are well managed, and not all businesses have highly volatile earnings. But generally your statement is correct.
Yes, the method is unversal. The only thing is the assumption used. For instance, past few years you might see a significant re-evaluation of property prices (should be even for REIT), and that shouldn’t be used as a normal growth rate. 

Good luck!