Bob, just a quick update on the steps I've taken with the iPad and the results I've gotten... I did indeed Reset All Settings (although to my surprise, it remembered things like my Apple ID for iCloud and the iTunes Store!), but unfortunately, it didn't seem to make very much of a difference in terms of the adjacent letters being recognised issue... However, this did lead to a *huge* discovery on my part, which was that I had had "auto-correction" turned off in keyboard settings, and when it is turned on, it is *much* easier to operate with the on-screen keyboard! Maybe this is why the majority of iPad users don't encounter many of the problems we've talked about in this thread...?
Lastly, I did try out SwiftKey to see if it was any better than the standard keyboard, and, although I certainly wouldn't want to jump to any conclusions or make rash pronouncements (as there must be many thousands or millions of iPad users using keyboards like SwiftKey very happily), it *seems* that unfortunately SwiftKey seems to suffer from the same key mis-recognition bug as the stock Apple keyboard (maybe they both share some backend code from Apple or something?). Just to show you that I don't think I'm imagining it, I'm just attaching a screenshot I took, where I was typing some random text into Mail... as you can see, I typed the word "rain" (it had auto-corrected it to this) but the letters it *thought* I had typed was "rajn" (just like the stock keyboard).
I didn't spend very much time with SwiftKey, but in the brief time I played with it, it seemed that while it was very snappy and responsive to use, unfortunately in terms of accuracy of recognition, it didn't seem all that much better than the stock keyboard. So now, I'm just making do with whatever the iPad will let me do (in terms of typing), with auto-correction turned on, which touch-wood seems to be working reasonably well (I have sent this reply from the iPad)! Many thanks again for your assistance Bob and trust you stay well also!