Yes, OPINIONS is a Scrabble word!

Letter values in Scrabble US: O 1, P 3, I 1, N 1, I 1, O 1, N 1, S 1.

Is it a valid word?

OPINIONS is a valid word in the official Scrabble dictionary (US), the UK Scrabble Dictionary and Words with Friends (ENABLE).

a personal belief or judgment that is not founded on proof or certainty
a message expressing a belief about something; the expression of a belief that is held with confidence but not substantiated by positive knowledge or proof
a belief or sentiment shared by most people; the voice of the people
the legal document stating the reasons for a judicial decision
the reason for a court's judgment (as opposed to the decision itself)
a vague idea in which some confidence is placed

Also: public opinion, popular opinion, vox populi, legal opinion.