Are both expressions "At the beginning" "In the beginning" valid and equivalent? The first "seems wrong" to me, but it has more Google results.
word choice - "At the beginning" or "in the beginning"? - English ...
The beginning of the century is a period of time which is short compared to the century but rather long otherwise; Some people may use this phrase to mean the first decade or even longer.
"At the beginning of the century" or "in the beginning of the century"?
grammaticality - "Upon" at the very beginning of a sentence - English ...
Can one use "Yet" at the beginning of a sentence as follows? Yet, he came late. Is this grammatical?
grammaticality - "Yet" at the beginning of a sentence - English ...
The "approximately" at the beginning of the list refers to each of the percentages, which have been rounded to a lower precision. I am wondering if the following comma is appropriate here, or generally when one is trying to apply a modifier list of figures.
The sentence where you used though at the beginning, seems incomplete. All you can do is, combine the last two sentences by removing the full-stop and starting though with a small t.
For example, the beginning of a race track is called the starting line and the end is called the finish line. There are of course more nuances involved than I gave in my answer, but the question was about the words in general, not in any particular shade of meaning.
The comma looks too accidental and unpolished. So again, the best simple rule-of-thumb is to avoid comma-after-so (indeed comma after any FANBOYS) at the beginning of a sentence, immediately following a semicolon, or immediately following a comma. That will nearly always align you with great writers and editors.