Okay I am now going to take time out from my very important posting frenzy in the Star Trek XI+
forum to explain to you all why Chakotay/7 works. For personal background in case anyone hasn't noticed I have always been J/7 and I have never been a Chakotay fan (other than saying he's good to look at). So I should be puking over C/7.
Chakotay is perfect for 7. Not perfect for the long term but perfect for where she is right now. He's kind, he's thoughtful, he's attracted to strong women and he will never hurt her. She is deeply wounded and unsure of herself as far as relationships and Chakotay has the patience, empathy and natural desire to dote on her that she needs. She has spent the majority of her life as one unit among billions with personal value having no reality. Chakotay will make her feel special, he will value her and relate personally to her as an individual and he's emotionally smart enough to understand that treating her that way is not a common thing but a part of her healing and growth.
Unlike other male suitors Chakotay is not one for ego. 7 will be free from him reacting personally to her coldness and misunderstandings. He is safe and he is easy to be in a relationship with compared to just about anyone else. He is not going to make demands on 7, rather he will be holding out his hand and waiting for her to take it.
Yes 7 had Auxum in Unimatrix Zero but that may seem more like a dream, a dream time within her enslavement. That was practice for having feelings as an individual, not practice for having a relationship in a real world.
What does Chakotay get out of it? As we know strong women are his thing, but this time he gets to be the strong man as well because 7 needs him. She's kick ass but she's vulnerable. He can give more to her than Seska ever needed or wanted. She may not show her appreciation but as she grows more comfortable in being in a relationship I think Chakotay will see her blooming and feel that he is
appreciated. It will be an important relationship for both of them and while it will not last (and doesn't in the books) they will part with no animosity and with a gratitude for the time they spent together.