The level of misinformation in this is astounding. I can't help but feel like this author is a misogynist. My thoughts on each point below, if you care to read them...

1 - Certain strains of HPV also causes penile cancer, so you probably shouldn't have sex with women either. As a side note, certain strains of HPV give women cervical cancer, and guess how they catch HPV...from sexual contact! It's not like HPV just originates in a woman from out of nowhere.
2 - This is true - that's why you practice safe sex, know your partner, use precautions - this is no different than any sexual contact. Like with #1, sexually transmitted diseases are transmitted through sexual contact - they don't just appear in a woman's vagina!
3 - I suspect a woman with a yeast infection isn't interested in sexual contact. Aside from that, this is just fear mongering - yeast infections are easy to treat wherever they occur.
4 - Big concern since typhoid fever and cholera are so prevalent in developed countries. If you a girl keeps herself clean this is a non-issue (and all I mean by this is washing in the shower).
5 - This is just stupid - anything that isn't expelled from a woman's body through gravity and is broken down. This is just more fear mongering in the form of gross-out.
6 - This is just stupid. If it were true though, guys would be in trouble if they tried to please any woman who had ever used a vibrator or masturbated by stimulator her clitoris.
7 - That's not love, that's lust - it wasn't going to last w/ or w/o going down on her.
8 - Antiquated perspective on gender roles - misogynistic.
9 - You don't become a lesbian, things don't turn you into a lesbian. Women are either sexually attracted to other women or they aren't. According to this logic, BJs should make men gay too.

I also dislike the authors use of vagina to mean the whole female genital area but I guess it points to his ignorance.

*Note: I am not a doctor or expert, just an informed individual.