Aaaah, Steffi Graf doesn't have the record for most GS single titles either, hate to burst your bubble. And what does a calendar grand slam have to do with anything? Serena has held all four major at the same time, to make the argument that they wern't all in the same calendar year is quite stupid. The point is to hold all four GSs at once, and she's done this. I believe the history books have it listed under the Serena Slam. No other current player, male or female can say they've done that. Heck, when was the last time a male player has held all 4 majors at once? The great Roger Federer hasn't, and heck Nadal hasn't even come close. Serena's the only one to have done it in the past 20+years.
You don't need to type in bold, I am not blind. Now, to address your points. First of all, Steffi DOES hold the slam record in open era. Most of Court's slams were AO, the least prestigious tournament of that time as evidenced by many all time greats not even attending it. So, yes Steffi does have more slams simply by virtue of playing in actual competitive era of tennis.
Second. Whether you like it or not, Steffi has done something that will probably never be repeated. 4 slams in one year. It's not "stupid" at all to bring up when it comes to GOAT discussion just like other almost impossible and impressive records (Borg's multiple Wimby/RG in the same year come to mind). The "Serena Slam" is a joke coined by Serena herself because of her failure to win the Calendar GS and her continued early exits at RG. I don't know anyone except the most blind of fans that will claim that "Serena Slam" is greater than CGS+olympic.
Third. I wish people on these boards would stop comparing men and women game. It's way more competitive, way more difficult to win a Grand Slam in men's game. The fact that even Federer couldn't hold 4 slams at once just proves how difficult it is (he lost to clay court GOAT in 3 finals and 1 semi during his peak). Serena dominated weak field for the last 2 years, hasn't ever encountered a true clay court specialist (because topspin doesn't exist in women game) and still failed at RG for the last 2 years. Men's game actually brought exciting finals, not straight set beatdowns by Serena of another mug or a headcase. Yesterday's Wimbledon final just further proves it.
Fourth. I thought this is GOAT discussion, so why are you bringing up "this generation" all the time. Yes, Serena is greatest of this generations, nobody is disputing the fact, however comparing her to the likes of Graf is absolutely laughable. She isn't even Navratilova's/Evert's league yet.