lilmod ulelamaid, how is this:
“Chalilah, no one said that their Mitzvos are worth nothing!!! I am the first person to say that every Mitzvah that every Jew does is worth an unbelievable unimaginable amount!!!!”
compatible with this:
“Better not to keep the Mitzvos than to deny the truth of any Mitzvah, which renders someone an apikorus.”
It is not clear that belief in God and acceptance of ol malchus shamayim is a halachically binding mitzvah. So I don’t know where you are getting this idea from. To push it a bit further– why is it so bad to be an apikores? Is there a mitzvah to not be an apikores? Well, that depends on whether or not there’s a mitzvah to believe in God. Which is a machlokes. Back to square one.
“the Chiloni and OTD Jew mentioned above are keeping some Mitzvos– they are keeping the Mitzvos of not denying that Torah is M’Sinai and not denying that every Mitzvah is from Hashem. And those are the most important Mitzvos!!!!!”
Those aren’t mitzvos for sure. There isn’t a mitzvah to “not deny” something. But regardless, a secular Jew who keeps zero mitzvos but doesn’t affiliate with liberal movements of Judaism doesn’t necessarily believe in God and in Torah MiSinai, anyway. (In fact, I would hazard a guess that the majority of them do not hold these beliefs.) As you already acknowledged in Qualification 3.