Hey @cyekmyster , thanks for the kind words and this wonderful comment. To answer your (great) questions:
I believe the correct etiquette is to post your article to one appropriate community, then click the "3 dots" underneath your published post and select the option to 'cross-post' it to any other communities you feel are appropriate. (There's an old article on cross-posting here: https://hive.blog/hive-175001/@steempeak/intro-to-crossposting if you want more on it.) - The main thing is to carefully read each communities rules and not to over do it. Some of them frown on cross-posting.
Many people have multiple accounts on Hive (these are generally called "alts" or "alt accounts"), but I've not seen many people post duplicate content from their alt. This may be because it 'spreads the rewards' across two articles, reducing the "big numbers" you could get from concentrating it onto one post. (People like big numbers, would you rather two post with 60 votes each, or one post with 110 upvotes?) Also, Hive is very 'anti-spam' culture, so that may be another reason I haven't seen duplicate content from alts. All that said, I honestly don't know the correct answer here, only that the feeling I get is that double-posting is not a great idea... but I have no solid data on this, you'd probably have to ask a long-time member of Hive, a witness or founder, or a whale. Hopefully I've at least given a bit of insight though, and at least you're upfront about what you're doing.
:) 🙏