At what point should one stop writing a first draft for a 5 minute corporate video? How much time and effort do you put aside for this aspect of the business?
How do you deal with script nuances and inexperienced clients? E.g., if a client asks you to clarify a certain section of the script, how do you go about it without sounding like a textbook on calculus?...
To me the First Draft should simply be a fleshed-out Outline. Presented as a First Draft with the inference of further revision or at least refinement, the script can be read and annotated by the client. Any serious revision might suggest a problem with the initial outline.
Scripted dialogue can be difficult. I have found that many dialogue issues can be sorted out during casting. Naturally it's important to have a near final approved script before you get to that stage, but necessary dialogue revisions become quite obvious to all when actors get the script. Subtle changes & nuance are fairly easy for everyone to accept at that stage.
Inexperienced clients are likely the norm - that's why they have come to you. So if an outline has been approved and then a first draft, subsequent requests for change can either be accepted or if problematic, referred back to the initial agreed upon outline & draft. Illogical or mistaken requests for changes should be resisted gently but firmly - my experience is that clients learn to respect that.
Finally it's a self-correcting problem: if the client likes you and the results are successful, they return; if not - they don't!