1. Perhaps you didn't specifically say it, but it's a tune that constantly plays when a class complexity topic arises or is discussed. As I said, there are some interesting ideas on paper, and it would be nice for SE to have a lot more creative liberty with classes rather than localize pre-existing ones from other games.
2. The funny thing about BLM is that while doing triple transpose was insanely difficult and you could pat yourself on the back for managing it, the return of it was hardly even worth it. More of a bragging right than anything else. There's a reason why certain classes are less preferred in certain fights. How can you ensure all classes are equally designed and offer the ability to play them regardless of difficulty or fight design?
3. I mean, perhaps it's a simple class but it still delivers what it was intended. SMN is not even all that popular in high-end content, and not because it's too simple but because there are better options that fulfill the designed role better, *cough* Picto *cough*.
As for SGE vs SCH, maybe their core idea is the same but they are really not all that alike beyond the fact they can shield.
For me, having reliable disposable heal/mits is important. Your design might work if the fights were adjusted to accommodate that change but the way some fights are designed now it will simply make certain classes a pain to deal with in the end content especially Ultimates where mechanics are very fast and you need to be precise. Nobody has time to shuffle a million cards and manage 10 bars.
"What does 'sprout' means here, though? Inexperienced? First timer? Or literally players with sprout icon?
I think it's fair to assume when you decided to step into these 'high end contents' you are required to have decent proficiency (not full mastery) of your chosen job, healers included."
I can mean one of those things or all of them. As for the rest, go in PF for a while and you will be surprised with the findings.