First, I understand how you must have felt to learn he might still love his ex. It sucks, but it's reality. At least you weren't married when you found this out. That would REALLY suck.
Second, sorry, but it sounds like you really went a bit overboard with the wishing he'd die thing and it also sounds like you kind of badgered him a lot before he admitted to it. Hey, I understand all of that. I really do, but for him, he's afraid to go against your orders and contact you again. If you want to be friends with him, you'll have to go to him and apologize for going ballistic and all that. I think you probably scared him. And yeah, I know all of it wasn't really your fault. It's a blow to the heart to learn that the one you care about might still have feelings for an ex. Still, you scared him and the only way he's going to consider being your friend is if you apologize for the nuclear bomb explosion of words you threw at him at the time. DON"T apologize for being upset though. He really did deserve that. He should have come clean sooner, but didn't, yet you KNEW something was wrong. He deserves to know he did wrong too, so don't take all the blame on yourself. Just apologize for wishing he was dead thing and that's it.
However, do you really want to be friends with someone who doesn't even know themselves well enough to know what their feelings are or for whom they have feelings for? Do you want to be friends with a guy who is kind of deceptive in that he wasn't honest with you right away, but had to have information pried out of him? I'm not sure he's worth being friends with, but that's your choice. I just think that being involved in his life at all is going to cause you more pain. It feels like a part of you still has hopes that one day he'll want you back again. You said, "I think for good this time"....meaning, the decision to make it permanent isn't coming from you. You say that based on what you think HE will do or want. Keeping contact while you try to adjust is just going to prolong your pain. I know. I've been there and it sucked out 3 years of my life for a one year relationship. Almost destroyed me and I wouldn't wish that kind of aguish on anyone else. Before you try to make friends with this guy, get your own mind and heart together first. Be sure that you're not going to get sucked into a hole created by someone who plays mind games or who likes to twist your heart back and forth. Be strong enough to resist it if he suddenly decides he wants you back before you seek a friendship with an ex. It'd be best if one or both of you are in a solid relationship with someone else first, so the temptation to reconnect is weakened.
Just my advice, but I really think that leaving the relationship choices up to him is going to be very detrimental to you. Take control of yourself first and you make the decisions. Don't leave it up to him. THEN, decide if you want to be friends or not.
Just my opinion, but good luck whatever you decide to do.