If this is newly written code not based on Skype code then there is clearly no copyright issue. Trademark is a potential problem but easily solved by removing the Skype name from the project.
Lawyers make such arguments all the time and it comes down to who has the time & money to take them to court, and defend against them, and then the judge is a human who decides, and is heavily influenceable.
Only the first one makes sense, and it has no relevance to the project we're discussing, so it's unclear why you say it.
No disrespect, just trying to understand your point here.
To me the point is pretty clear: Copyright law is also used for chilling effects on recalcitrant projects.