This thread will cover his feats, strengths, and weaknesses including Manga, Novel, and Anime info.
A lot of his feats are in his abilities section, so I will try to only elaborate and bring in more feats.
Can use Tsukuyomi on anything with a chakra network, as he used it on insects in the Novels, can use Tsukuyomi to make 77yrs go by in 1 real life second, and if he kills said person in Tsukuyomi their brain will shut down and die in real life. His Amaterasu can have controlled range of temperature, as he used it to instantly burn through a fire breathing toads stomach. He can form his Susanoo fast enough while blind and nearly dead to block Kirin which strikes as fast as real lightning showing Itachi's incredible reaction speed and reflexes.
That's a start. Feel free to add more.. this is not a debate thread this is a facts thread so no arguing or debating over what is posted.. only if it can be legitly proven wrong or right.