Re #20, the most important aspect of a callout is to report the system condition enabling both pilots to have a common understanding of the situation. That can be very difficult depending on the context of the situation and what is actually happening.
The ‘golden’ mantra for the need to understand the FMA requires additional clarification with respect to what the aircraft auto-systems are doing, have been programmed to do, or the crew’s intention and the expected changes; it’s far more important to understand what the aircraft is actually doing than what the FMA indicates.
A problem in calling all ‘normal states’ is that this can lead to ‘wish think’ - you think that you have said the words, but may not have; or ‘hear think’ - you believe that an expected conditions exists, but in fact does not.
The better approach is to only call the undesirable states - ‘no glideslope’, at a time when it should be armed / engage. This has the advantage of reducing ‘callout clutter’ (soggy SOPs), such as GS armed, GS engaged, GS star/dual, etc.
Unfortunately this ‘deviation’ only method requires that both crew have a common understanding of what is intended; standard procedures could help, as might a good briefing, or improved cross crew communication; so FMA callouts are used for this but may not be the best method.
And then again with positive calls there is potential confusion by intermixing normal and abnormal states using the same words. e.g. GS mode armed / engaged vs GS deviation in auto flight or the GS component of an unstable approach.
Your choice, but choose carefully.