I have a few ideas on new optional items and a few things, and from what I was thinking, they are mainly FF7 ideas.

The Strife Armor is of course Clouds stuff, and looks better on guys. Why not make it male only, with the option of trading it in to the Calamity Salvager to get a Tifa AC set.
Or have it like the cascadier vouchers and trade them in at mor dhona for one of them with the ability to switch them at the salvager.

With Dark Knight coming soon with Heavensward, perhaps a Buster Sword to complete the look?

And since Heavensward has personal airships that look almost like flying motorcycles, why not add in an optional flying mount that looks like the Fenrir motorcycle.