I have hunted trees similar to what you describe, and would do so again.But I haven't seen the tree that you are speaking of.Only you can really decide if you feel safe, and like others said, if your gut is saying something ain't quite right you're better off not trying it.There's nothing wrong with a good ground blind.I doubt I'll ever give up treestands, but the more I hunt from a blind, the more I like it.
If you do decide to hunt it, I would climb leaning towards the tree, over 90 deg., if I understood that part of you question correctly.Climbing leaning away from a tree is unsafe and uncomfortable.