I never figured out nursing while wearing her, but the moby did seem like it would be the easiest since it's stretchy and more forgiving. If I were to try it I'd make sure when you tie it on that it's loose enough that they're at the right level to your boob (when I wore Kate in the moby she was SUPER little and I wanted her up high on my chest). Other than that I would think just experimenting with it!
And yeah, I think any front carries done with a wrap should be able to be done with a moby.
Obviously if you try something and it feels too loose (since the moby is stretchy) then that's your answer, lol.