Does having official social media account such as Twitter guarantee the legitimacy of the project?
Of course this one could be a factor of such community. Verified account of a project the gold one of course not the twitter Blue.
You can not tell the difference between the real owner and the impersonator because they're very smart to use very similar Username that one can hardly notice the difference.
Of course we can. Im a long time twitter user and obviously will discern the difference of an impersonator and the original. Of course is Ive already followed the original, now the impersonator will pop anytime on the original posts, and from that youll see that you arent following him.