As for the pronunciation of "schedule", I think the American usage of the "sk" sound versus the British "sh" is due to the influence of the German language in American colonial and early independence periods. Noah Webster apparently settled on the "sk" sound for his first American dictionary due to German influence. Since English is a Germanic language, it is likely that speakers of Old English used the "sk" pronunciation. The Angles (as in Anglo-Saxon), from which the name English is derived, were a Germanic people from Jutland (Denmark). The British "sh" pronunciation may be the result of Norman (French) influence.
There was even a strong movement to make German the official language of the US in its early days. I read somewhere that, as recently as the US entry into World War I (1916), Cincinnati, Ohio had six German language newspapers. They went out of business when speaking German became unfashionable.
I can't think of any word beginning with the letters s-c-h that Americans generally pronounce any way other than "sk". American radio and TV networks often use British reporters for their European coverage, so I hear "schedule" pronounced with "sh" frequently. Doesn't bother me; the accent has already identified the speaker as British. The British aren't as consistent as Americans; pronouncing "school" and "scheme" with "sk". The difference may be due to the letters that follow s-c-h, such as the "dj" sound between the two syllables of "schedule".
There is probably more confusion in the definition of words between Americans and British than there is in pronunciation, but I wouldn't want to start anything.