A medieval EP must have...

I really agree with @MyriadSims

I think a lot of items in the poll list could apply to any pre-Industrial Revolution era and you want the EP to really feel like it belongs truly to Medieval. So chivalry, build mode additions that give you the ability to make decent castles.

With the stuff on dragons, I feel like there's a question of whether you're trying to make a Medieval pack to satisfy Historical simmers or a Medieval Fantasy pack to satisfy Occult lovers. My guess is EA would choose the latter over the former. As a historical simmer I would have no use for dragons but endless us for stuff like the lute, archery and other realistic stuff people have mentioned.