I am posting each of my suggestions separately. I realise that makes a large number of posts, but it ensures that no suggestion gets lost if there are a lot of comments.
Suggestion 20: It would be nice if heroes that you no longer wish to use would not be lost forever. I would like to se an inactive option; maybe label them as ‘On Pilgrimage’ or “At Crusades”. Then if they are desired again, they can be bought again (I suggest at half the inn value, after all they were your vassals previously).