I was tempted to answer "Yes." to both questions, given this recent amusing post in the Tech Vent and Rant thread:
https://www.mobileread.com/forums/sh...postcount=1917
Automatic adding and converting are built-in Calibre features you can set in Preferences -> Adding Books.
So, I think you'd need a chain only for steps 4 to 6. The step 5 ("Apply" font of choice), can't have a general solution that would work for all books, IMO. As for "Remove rating", this can be done easily, by adding to the Chain an action called "Single field edit", as shown below:
To download metadata, you need to insert (Create) a new module after installing Action Chains plugin:
https://www.mobileread.com/forums/sh...9&postcount=28
Then add an action called "Download metadata" as the first step in the chain.
And you can also add an action to select metadata source, by installing the
Quick Preferences plugin.