First, thing that pops into my head is money, 911, 3 top hits on liinkedin google, you sound like you're doing well for yourself. Whatever happens, if money is mentioned, walk away.
However, i have 2 sides to me, a real nasty **** you kind of side that says it's all BS and ignore it, who needs that kind of hassle in life! The other side of me says, people make mistakes, sometimes it takes a long time to figure out how to deal with them and maybe it's worth the risk to see him.
Have you spoken to your mum about it?
You say you don't have kids, I have 2 and you're right, I couldn't live without them but a small part of me does think if anything happened would they be better off without me and this back and forth in their lives, could I cope mentally saying goodbye each time? You really don't know what you would do until it's happening, and there may be stuff that happened between your mum and dad that you don't know about. Maybe she told him to stay away or maybe he thought that keeping you away from that side to his life would be better for you, and it certainly has been.
Why doesn't he phone you and have a chat over the phone?