For code to use an Excel to store a word list for Find/Replace operations, see:
https://www.msofficeforums.com/word-...d-replace.html. Compared to the approach there, it seems you'll need to either keep the workbook open while processing or create multiple find arrays in Word, one for each of your rules 2, 3 & 4.
As indicated in my previous post, though, you're liable to have problems implementing your rules 2, 3 & 4.
It's also not clear how you propose to do the line numbering. Word has an automatic line numbering feature you could use. However, you also need to be aware that what appears on one line on your PC could be on a different line on another PC. That's because Word uses information from the active printer to determine the page formatting. And, of course, if one inserts a 'front page message', that could mess up the line numbering unless a Next page Section break is used and line numbering on the first page is disabled.