>fix the horrible inconsistencies in the way autocorrect works (or, please, offer a system that just underlines words-thought-to-be-wrong without changing them, and let me tap on them to change them, or use the current autocorrect system but let me tap on a word to un-"correct" it, the fact that the current system just changes what I typed and gives me no recourse to fix it apart from laborious deletions and re-typings, which I often have to do 2 or 3 times, is just haughty and offensive)

Android has this same problem and I wish they'd fix it using your suggestion. It would make typing so much better.