Is he considered a hypocrite, one who denies authentic hadiths that conflict with his own ideas, hates the Sunnah, and fears people's words more than Allah's?

If your companion fabricates lies against established Sunnahs and denies them, he is in grave danger. You must advise him by clarifying the severity of his innovation, the obligation of submitting to the rule of Allah and His Messenger, and of yielding to what has been authentically reported from the Prophet (peace be upon him). He should refer the matter of the authenticity and weakness of hadiths to the deeply knowledgeable scholars in this field. If he persists in his conduct, then beware of his companionship and instead accompany righteous people who venerate the Sunnah of the Prophet (peace be upon him) and judge by it. Do not preoccupy yourself with judging him, but rather with what benefits you. Advise him and make clear to him his error and deviation.