OK, now I'm worried (in regards to AST buffs)

[Reiryuu]

yeah right, correct, but you will still be able to drag em in your Toolbar right?
so ... you ... kinda lose nothing ... or not?

You're missing the point. Each job gains skills as they level, yes? Protect comes at 8, Cleric stance at 4. If those go into the "Healer Role" skill pool, The conjurer job no longer gains abilities at 4 and 8 that are unique to it like Arcanist(SCH) would (AST technically would to, but since it starts at 30 it's not as obvious and the first dungeon is 15 for level synching.) Thus Conjurer/WHM would need abilities that are unique to it to fill in the gaps.