I'm a little confused here - did your parents do the same as you're doing or did they take the liberal approach that you don't want to take?
Either way, out of curiosity which drugs? I've had a phase myself with LSD and 2cb (the latter probably more recreational) and dabbled with mescaline and mushrooms, but never liked ketamine and never been keen enough on self discovery to get involved with DMT or similar tryptamines.
A shame, they're definitely well above average, and as said his agenda is towards the religions, not towards God, at least in the books and a couple of interviews with him that I've read, although I'm sure there are a lot of other articles where his views are either misinterpreted or actively misrepresented.
My parents raised me the same way I am raising my children... and I can tell you from actual experience that it had no impact on my ability to make my own decisions when I reached young adulthood. Even though they had taught and showed me a Christian way of life, I completely abandoned it for a life of "finding myself and my spirituality" through "mind expanding" drugs like LSD, mescaline, and peyote. All of those things are simply self destructive, and while they can lead to some fun times, and some very deep thought... they ultimately are spiritually empty. When I almost died I had my parents teachings to fall back on. I was able to re-evaluate what they taught me, and I made the conscious choice to study the bible and believe the word of God.
That's the background that I want to give my children. They then will have the ability to make informed choices (once they are old enough to actually make informed choices, and no matter what you may think... a 9 year old boy is not fully capable of making informed choices). I will respect (even if I don't like) any informed choice that my sons make when they are adults.
About the books... like I said... I have about 30 books still waiting for me to read them... I have no reason to read a book by a guy who I completely and utterly disagree with on the most important aspect of my life. Am I saying it's a threat to me and my beliefs... absolutely not... he could never sway me. What I'm saying is that I consider him a poor influence on impressionable children and I don't need his works in my life... it's that simple. Am I missing much... considering how much good fiction is out there... no, I'm not really missing much.
And he is known to be an extremely vocal atheist... and that is not a misrepresentation... it's a fact (I'll try to get my sources... it's been a while since I've read the interviews). And being an atheist is by definition being against God. It's not the disbelief of religion... it's the disbelief of an all powerful creator.
Just my opinion... and as always... you are able to raise your children any way you choose... but when they get to a terrible time in their life, and they have no strong basis to fall back on (whether is be Christianity, Buddhism, or just a very good teaching of respect and love, etc), they face a much greater risk of not being able to rise up out of the terrible time. I've seen it, studied it, and experienced it with other extended family members.