Almost certainly I can. But right now I'm in high school, so I don't know that many people who qualify.
Um... assur means you can't do it. It's not less severe than "forbidden", I don't think. It literally means "bound". It's important to note that it doesn't mean something's morally wrong, but in this case, independent of the prohibition (non-literal translation of the noun form, issur) the act of reading foreign philosophy without knowledge of the corresponding arguments in one's own can cause stupid questions, not smart ones, and is considered to be wrong, not just forbidden (in my father's circles, anyhow).
I don't know about "frum". Badly educated and mistakenly chumradik is more like it.
The hardest part of reading things l'havin ul'horos is that I can't recommend them to anyone else because it's assur for non-learned people to read them (possibly even non-Jews, in this case). And yes, iarwain1 is correct that apikorsus is a thing and an apikores is a person. But thank you for translating.
I'm an Orthodox Jew (Modern Orthodox). Since Mr. Yudkowsky's work is - obviously - apikorsus of the highest level, I read it l'havin ul'horos, mostly, but enjoy the thinking in it anyway.
That would work... but the Chareidim don't actually believe in their defenses (they flee places getting bombed and leave the soldiers to defend people's lives), nor are these defenses backed up in any way by halacha (they're misinterpreted that one text they use as a source). Also, they don't allow anyone in their community to go into the army. Ever. And they don't let non-Chareidim join them in their learning for defense, either.