1) In this case "come back" is not an action someone can do to the word, so it doesn't grammatically apply as an instruction. You still have lots of options that do: X comes back, X coming back, turn back X, X turned back, etc.

2) Spoonerisms are named after Spooner, not Spoon (and if this isn't a spoonerism, I wonder why Spoon is capitalized)

3) I don't know for sure not knowing the solution, but the article was probably ok here. No harm in removing it either way.

7) I do not think "astro" works as a synonym for "star". Sure, both are certainly related, but they don't mean the same thing as far as I can tell (astro- is "related to stars").