People couldn't understand how I was actually using a Unix system to show my slides with, so here's the system I use. What I am about to tell you is mostly my opinion. It includes both general philosophy and concrete tips. I do not expect all of you to agree with me all the time. Choose a style and stick with it.
Consistency is critical.
That person shouldn't be maintaining a language they don't understand. Now throw it out. Feel free to hack and use. The original troff slide macros were done by Rob Kolstad. I've used them for at least a decade.