2. Round eyes are the most advanced of the three pupil techniques (what are the three pupil techniques is unclear). Ootutuki Hagoromo, the founder of Ninjutsu, has the legendary pupillary technique, and even Jiraiya doesn't think it really exists. In the recent cartoon, among the three teenagers rescued by Jiraiya, Nagato has a round eye. (Now Paine's eyes are round, so Jiraiya speculates that Nagato is Paine)
3. Red glasses are similar to round eyes, but it doesn't reveal whether they are round eyes or not, nor does it say anything else.
4. Many YY people say that Naruto has blood inheritance, but now there is no evidence that it is only in YY.
5. White eyes are better than sharingan's. This is all I know for the time being.