His Katons are as good as Itachis, but he has some powerful Ritons too. Sasuke is more talented with Ninjutsu than his brother, hence his Amaterasu is superior. Its the other way around with Genjutsu and Tsukiyomi.
I will give him that. But overall Sasukes Ninjutsu > Itachis Ninjutsu.
Nope. Totsuuka has to pierce through something in order to seal it. I dont think it would be able to pierce through fully formed Susanoo.
I disagree greatly , Sasuke has more Ninjutsu including lightning ... Yes he does, Better than Itachi NO, you're taking away the experience factor. The only reason Sasuke's Firball seemed to be more powerful than Itachi is due to 3 reasons :
1. Sasuke's CM
2. Itachi's Sickness
3. Itachi was focusing on two things, getting Amaterasu ready, and having to keep the Fireball while doing that.
Sasuke has MILES to go before reaching Itachi's level. also if Itachi didn't make a clone when they were doing their Shuriken clash, he would've over powered Sasuke's Shurikens. that whole fight Itachi was doing 2 things at a time. while letting Sasuke do whatever Jutsu he wanted.
Now Totsuka blade will be able to seal Sasuke's Susano along with Sasuke him self, Why? Tatsuka blade is an ethereal blade that pierces through anything, see it's not actually hitting the person it goes through him. ( see below )
It is an ethereal weapon with an enchanted blade capable of sealing anyone it pierces.