A lift will be safer but also more of a pain to set up. It could also tear up the lawn if you dont put boards down. I would only rent a lift if you could use it for a whole weekend worth of jobs or if you are uncomfortable being on a roof or ladder.
If you end up working on alot of steep roofs like the first house I would invest in a good climbing rope and harness. Then you could do everything from the roof and not have much to worry about.
96 gmc 2500
16ft PJ utility trailer 2009
2011 Snapper 200xt 61"
Great Dane Chariot 52"