User blog comment:Master Sima Yi/Assassinews 05-08-'14 – Assassin's Creed: Rogue announced/@comment-24760042-20141014210122/@comment-733050-20141023204300

These can be answered by reading Haytham's article. The answers are yes, Haytham knew his father was an Assassin, and no, he used Miko (the man he killed in the Royal Opera House)'s Hidden Blades.