"Unwelcome liberty", "taken with"

Question

His works were praised by many literary critics as fresh, inventive approaches to the form of the novel. Others, however, dismissed his works as simple retelling of local tales, full of unwelcome liberties taken with the details of the well-known story lines.

I am having problem with the bold part. My understanding is that his work is being criticized by some people because the work is written too freely (without following the novel forms that were used to be followed) and this "free (=liberty)" was combined with details of well-known story lines. Am I understanding it correctly?

Answer 1

"Taking liberties" is an idiom. It means to behave in an unduly familiar or easy manner towards someone or something, or to treat something freely, without strict faithfulness to the facts or to an original.

I'd suggest the latter definition (in bold italics) is closer to what it means in your example. So yes, I think you have understood it well enough.

Answer 2

He didn’t retell details of well known story lines faithfully. He took liberties with well known story lines. These liberties were unwelcome. Together: His work was full of unwelcome liberties taken with these story lines.