Agreed, I think they tried to find a use for retainers and shoe horned an AH into them as best they could, it still ends up being quite convoluted (especially for new players)

I agree about vendors selling gathered materials, I can see why they have done this, because it is convenient for crafters, on the same note I think they should reduce the amount of quests reward gear as well as this is marginalising the economy to the point its barely worth crafting any more.

Again Materia is pretty useless expect for pre end game gear and most times aetherial and green named gear will get you through until darklight.

I disagree with the gil aspect of your post though, as a crafter I can make money quite easily so don't think there needs to be any changes there.