Regarding the Mc and Mac question, I have a book printed in the mid 19th century which spells the same person's name in three ways, all on the same page, MacGibbons, M'Gibbons (not an apostrophe but an open quote) and McGibbons (the c , underlined, is placed half way up the line). It would appear that the open quote was eventually seen, incorrectly, as a c, hence the modern usage, as in my name, e.g. McLean.
Incidentally I have an uncle and nephew who use MacLean.