safely and legally, you can check platforms that host Kodansha titles or general licensed manga services: Crunchyroll Manga
Not significantly. While the manga offers exclusive bonus chapters and deeper internal monologues (especially for characters like Misato), it generally covers the same timeline as Season 1 of the anime. As of now, there is no "Season 2" material in manga form, though the fandom is eagerly awaiting a potential sequel.
: