Reverse Tab ⇤ is still with us, above the Tab ⇥ symbol. It is at the top to indicate that it is generated while holding Shift.<p>Many people have got the misconception that <i>both symbols together</i> is the Tab symbol, though. There is even a symbol consisting of both close together in Unicode: ⭾ and many PC keyboards that similarly have both arrows closer together than on keys with printed symbols generated with and without holding Shift.
(Apple has been printing only ⇥ though)
Insert is gone? I have it here... though I can't remember the last time I used it. I never found much reason to think "I want to overwrite existing text as I type"
"Insert, now gone"? I press the INS key, I overwrite text, it's very useful. Though thinking about it I suppose that really turns insert mode <i>off.</i><p>"Key beep" sounds horrific. :D