"it reflects the opinions of its author and social context of its age."
Dishonest statement. Ramcharitmanas isn't some personal imagination. Every word of the text is part of a continuous tradition. Every statement is based upon the fundamental scriptures of Sanatan Dharma.

"नानापुराणनिगमागमसम्मतं"
in accord with the various Puranas, Vedas and the Agamas (Tantras)
- Balakanda (Manglacharan), Ramcharitmanas