well, first off, ask yourself this...
would you still like him if he just liked you as a friend. But meaning this is a guy that calls a friend a friend, when he cares and maybe even loves you and not a friend because he's exchanged words with you. He sounds a little like me, with a lot of respect for a female friend and he truly seems to value you as a true friend.
Let me just say that in my life, it sucks when females only want you to look at them as dates or pursue them romantically, regardless if they actually are attracted to me or not. Also, I hope your attraction, if that(I don't see mention of anything in that sense) isn't because he is nice...niceness just makes people comfortable into believing they are attracted...yes my case too. Women think they are attracted to me but it's just because I'm harmless
So just ask him as a friend when you guys are hanging out together and it's fairly private. Just ask him what he thinks of you and leave it at that. Meaning you'll know whether or not to ask other questions based on the answers you'll get.