@daylily, I love your reasons for liveheading! I hadn't given a thought to reason #5 (the chance of breaking petals when deadheading).
A good reason for either liveheading or deadheading is that you do not want unwanted seedpods taking energy away from the plant. (having a lot of seedpods might decrease the chance of rebloom is what I was told).
I had never heard that removing spent blooms would leave it susceptible to infection or contamination. And I use the method of removing scapes that Juli and Julie explained. If the scape does not come out with a gentle tug, I leave it.
I can't wait until I retire so I can livehead (one more summer after this!). I may do it on a weekend night so everything is fresh on Saturday or Sunday morning. They are not even fully opened when I leave for work Mon thru Fri, so I don't get to enjoy them until after 4:30pm at night those days. Once it turns dusky, I still get to enjoy them because they are easily seen in low light. But by that time, I'm not going back outside to fight the mosquitoes to livehead, lol!