One email: I do not have a good answer to those questions because I have not taken the time to study them in detail.
Later email: ... you are in pursuit truth, whereas I feel sure that I have found it. ...
... "Make sure of all things: hold fast to what is fine."
My goodness! His head's all over the place. How can he have "made sure of all things" and have "found truth" regarding the issues you raise if he has "not taken the time to study them in detail"?
He has not educated himself sufficiently to competently address your concerns. Perhaps ask him if he can refer you to somebody who has bothered to look into these matters who could help you. Time to cut him loose - as far as this line of enquiry goes, anyway.
I agree with those that say he's scared. He may not have looked into those subjects because he SENSES where they will lead and he knows he won't be able to cope with what he'll find out.
Eccl. 1:18 (NASB) - " ... in much wisdom there is much grief, and increasing knowledge results in increasing pain."