Itachi's skill in Shurikenjutsu in my opinion is 1 of his Counters against Flying Thunder God, it requires a sealed Shuriken for Minato to Teleport, yes he has shown us that he can use multiple Shurikens at once where he can teleport towards but remember when Sasuke threw Shurikens towards Kabuto and Itachi countered them, with his BACK towards Sasuke (so he couldn't even see them). I am certain that Itachi can counter Minato's Shurikens and make Minato go where Itachi wants him to go.
Itachi is also unmatched in: Genjutsu, Speed of waving handseals, Being able to deduce the inner workings and weaknesses of powerful techniques, even while under pressure.
Sorry but Itachi OVERALL is an unmatched Shinobi. He has shown things that people thought were impossible, everytime he had screentime he showed us new Uchiha abilities that were even better than the previous ability he had shown. Itachi like you said has find the Rinnegan's blindspot and was able to hit it DUO to is Shuriken skills, with this Itachi has shown us that Shuriken skills still matter in combat, even with all these powerfull abilities.
I do like Sasuke very much he and Itachi are my favorite characters in Naruto, however Sasuke is no match for Itachi in this feat, Itachi was able to make a Bunshin during the Shuriken battle, Sasuke was totally surprised by this, with this alone Sasuke has shown that he is inferior to Itachi.