No, the word "familiar" is the problem. Use the word "similar" instead.

You could say "You look very familiar" or "You look very similar to someone I know" But "You look very familiar to someone i know" is wrong because "familiar" can't be used to compare things (unlike "similar")

There are 2 possibilities: 1- You look very familiar to me. 2- You look very similar to someone I know.

No, I don't think it makes sense. "Familiar" is an opinion. So it's like saying "--- It seems that a friend of mine would think that he already knows you" It has grammar, but it's almost science-fiction...