By all accounts Houdini was a very impressive and exciting stage magician, by virtue of his brilliant showmanship and flair for publicity, but he wasn't particularly innovative, in that he generally adapted techniques of others rather than inventing his own. Neither was he unusually adept at sleight-of-hand. His "King of Cards" title was apparently a bit of an overstatement, although he could perform some flourishes on stage with a panache that marked him out to laymen as some kind of pasteboard genius. Among his peers, like Dai Vernon, Doc Daley, Cardini, John Scarne and so on, he was not considered to be much of a card man.
On the point about stunts, escapes and the like, to my mind, they take the same place for the stage or TV magician as flourishes do to a close-up worker, or a genuinely psychological effect does to someone like Derren Brown. In other words, they prove unequivocally to the audience that you possess a high level of skill in your chosen field. Therefore your audience are more prepared to be amazed at your other effects, rather than merely questioning your method. They know you have almost unbelievable talents, so they feel themselves almost unworthy to accuse you of using some trick prop or another such subterfuge.
