I get why they are using King James language but a button to translate to modern English would help.
Should be “when thou expectest it least”
lest thou tear thy hair
Should be “lest thou tearest thine hair” as I seem to recall the h sound acting like vowel for words that sound different based on what follow them.
lest grievous harm befall thy program.
Should be “befalleth”
"The third person sing. Present, ending in th, as taketh, bringeth &c. is now confined to sermons and grave discourse." - John Hunter, Text-book of English Grammar 1848
My favourite -eth, from the start of Moonlighting's Atomic Shakespeare episode:
Good morrow, sir. I'm Lucentio, come hither for to see fair Padua, pleasant garden of great Italy, to seek out and happily begin a course of learning and studies herein.
You've mistaken me, sir, for someone who careth.