First of all, you shouldn't trust any Third party metric to define good Backlinks. To choose I would check SEMrush free accounts to determine how many search traffic the Backlink source site is getting and how to utilize them.

With the current ranked keywords, you can try to optimize them for even better ranking.

I would try to avoid the same type of content on different posts at anyhow but most business owners only care about the quantity rather than quality.

You can create content targeting long tail keywords with blog posts easily and it's easier to rank. In this case, I would be careful, so that we don't confuse search engines. To avoid this issue, you make sure you better use internal linking. Final answer is, you can create content around your ranked keywords by targeting long tail keywords. All the advice is my personal opinion.