Not an Itachi or A fanboy, just putting that out there.. but you should at least post the links as evidence for your claims of a characters powers.
First since when does speed allow you to escape a Genjutsu, yes you can dodge its targeting but all Itachi has to do is point his finger or meet your eyes and your in it, while A could dodge the finger point and avoid eye contact, being able to move far enough to avoid the general direction of a finger point while watching your opponents feet to see when and where he points requires not only speed but knowing all of your opponents genjutsu techniques and how they work. Well obviously you don't want to meet the eyes of a sharingan user too much in battle but doing so while knowing and avoiding any others he might have, is very questionable.
Agree, Susanoo does work defensively against A's attacks
You must be registered for see links
But don't forget Itachi had an impenetrable Susanoo defense with the Yata no Kagami, that he could use at any form of Susanoo even when he was running low on chakra.
You must be registered for see links
Offense as well as defense should work for Susanoo, A's Raiton armor is strong but it can be pierced by Ninjutsu.
You must be registered for see links
Agree, yes A can dodge fast firing Ninjutsu like Amaterasu, However notice that A dodged Amaterasu rather than it hitting his shield and being ineffective, this proves that you don't need Raiton to pierce his shield because otherwise he would have let it hit it and do nothing. So Amaterasu, Kaiton, and Totska Blade are all able to damage A.
You must be registered for see links
I reread the A fights and I don't see anywhere where it says he has "Bijuu Level Chakra" He's Raikage certainly he has quite a bit but Bijuu level? The only human who's been said to have that much chakra is Kisame. If your exaggerating a little I understand but if your trying to prove that A is better than Itachi from a logical perspective you need to avoid blatant exaggeration... You know what I mean?
And Itachi is Ranked in the manga as an S-Class ninja, and can perform Tsukuyomi, Amaterasu, Susanoo, Izangi, and Multi Layered Genjutsu all of which require far more than "Chuunin Level Chakra"
A vs Itachi would have been a great fight, however there would be no "Domination" from either side... Every character has his or her flaws in ability and unique specializations, no two in fiction are ever the same however when comparing the qualities of two characters for any form of competition or skill, since we aren't the writer and can never truly know the outcome of said competition, unless it actually happened before, we have to use what the writer has given us and restrict ourselves from opinion and use logic when considering abilities.