Having learned to touch-type on a British "Imperial" telecommunications typewriter (all letters upper case) some fifty-eight eight years ago, and enjoyed many an hour at many a desktop Mac's "big, bulky, heavy, thick button keyboard" since 1997... I too find that the ultra-slim aluminum desktop keyboard that came three months ago with my refurbished iMac 20" Intel 2.66 is not conducive to touch-typing... as for its mouse... I prefer and use a KENSINGTON Expert Mouse Trackball - optical - wired - PS/2 USB Model K64325...
Dang, that's almost my story, too. My folks had two of those manual typewriters, and at 4 or 5 I didn't have enough finger strength to get the letter imprinted on the paper unless I used two at a time. And forget using pinkie fingers altogether. We got the Osborne 1 which would have been about the same time as the Kaypro, and I could actually type on that keyboard. I think the worst keyboards were the membrane types on the Atari 400's. Hate, hate, hate.I started only when my dad used to bring home an Apple IIe and this other "portable" called a Kaypro (can't remember the spelling!). My mom used to use a typewriter with the arms that whaced the ribbon. I sort of started on that, but was more fascinated with how it worked.
Anyway, back to the new keyboards. I am currently typing on my old 12" PB G4 which is missing the "p" button. Anyway I have only tried the new one at the Apple store and didn't have any problems. I had been thinking of getting a new keyboard to connect up to this, but have never gotten around to it.