No Good Deed - I wouldn't get your hopes up about Lett getting kicked off the Governing Body anytime soon. He'll need to string out a lot more rope before he can hang himself and embarrass the Governing Body beyond the point where they will continue to put up with him.
Fred Franz was this same style of kook. The difference is that Franz wrote his own material, where (especially at conventions) Lett reads the same talk that any other speaker reads at other less important convention locations or in foreign languages.
I have no idea who actually writes the scripts and talks for these streaming videos, convention talks, or other special presentations. I'm sure there is a staff of writers who do this kind of work and then prepare standard formats with notations for the speakers to use (emphasis, gestures, pauses). I know from several sources that lesser speakers must present talks exactly as written and there are script checkers listening and verifying that every word and notation in the script is presented as noted. Any deviation from a prepared script can result in loss of privileges and removal from future speakers lists. Whether this applies to Governing Body special scripts written by the GB members themselves - I don't know. Maybe someone can enlighten me.
This practice has reportedly been extended down to the half-hour "public" talks (that term really does not apply any longer) given in Kingdom Halls. In the past, brothers would take the outline and add notes and their own emphasis to certain sequences, often adding scriptures or side remarks to flesh out the talk and make it less boring. I've heard that is not allowed any longer. While being on the public speakers list is quite an honor for elders and MSers, they can be pulled in a blink if they try to get creative in any noticeable way. This obviously does not apply to GB members and their towel boys.
JV