There are a great many things that we do (and don't do) at my airline that are against industry norms. Presumably because we know what we're doing, and the rest of you have it wrong (sarcasm, for those who missed it).
I do think that landing vs continuing is overthinking it a bit though. We say "9000 for 8000" knowing that if ATC gives us another altitude before getting to 8000, we'll have to abandon the original plan.
You do raise a very good point on the FMA. Ironically, your example is one of the only 2 times we read the FMA aloud. (Only 2 US airlines read FMAs)
Regarding "formal compliance", I realise that in Europe, Asia and Australia, it's quite highly regarded, but here, when forced to choose between the letter of the law, vs the spirit of the law, we go with the spirit. That reminds me of a clip I saw on YouTube only last night.