Sasuke didn't have MS when he fought against Itachi. This gave Itachi a huge advantage and yes he probably could have killed sasuke if he wanted to. Just because he got Itachi's eyes basically because Itachi let him win doesn't take away how strong he is with EMS.
Madara got his EMS by his brother giving him his eyes. Does this make madara overrated? I think not.
BTW I am by no means a sasuke fanboy, i just think your thread has little basis.
As for Minato, So what about him marrying Kushina? I'm sure Kushina was able to teach him a lot of sealing jutsu long before they got married, they had been together since they were kids. Just because he learned his sealing techniques from somebody, it doesnt make him weaker. Most ninja learn their many techniques from their teachers.
Naruto learned rasengan from Jiraiya, who was taught it by minato. Naruto then took that technique to another level with rasenshuriken and odama rasengan. Sasuke was also taught chidori from Kakashi but has also made enhancements and his own versions of the technique. What is your point here?
