I Never said or liked when Sana was called characterless.she has not done any thing that she should be called that.
But looking at the Episodes I must say she is not Naive either she very well knows what she is doing .she wants to flirt fine, she wants attention no harm all girls at their 20's are like this only.
She must confront people (housemates) when she is questioned about her link ups with mens inside with all dignity and respect that she herself has never had any such thing in mind it's just plain friendship.
Bhaktiyaar came, Delu's mom came and both linked her to Rajeev ,when she is Just 25 and is it o.k if she is spending around late night hours with a 40+ man in name of "I enjoy flirting" or "we are Just good friends".(I don't buy this).
If people are charging her she knows it very well from where fume is coming and she should have backed off long back with Rajeev.
I repeat again she has not done any thing that should categorize her in genre of "Characterless" but she is not Innocent either.