Proper setup of multi doman site

I would suggest only combining topics that are somewhat related. For example, your natural remedies and farming might go together, depending on what kind of articles you write. Videography and outdoor Amazon stuff seem like they are totally separate topics.

You might be able to set up a MultiSite and map the external domains. It’s a bit tricky to set up but once you get the setup done it would be a single place to update everything.

Personally, I would keep either the natural domain or the farming domain and combine those two into one site – 301 redirect whichever one you don’t keep – and then I’d keep separate domains for video and affiliate. If MultiSite domain mapping is too big of a headache just keep 3 separate WP installs.