In a wordly sense, relationships are and will always be a HUGE mess!
If I had to look at relationships and establish a healthy one in a worldly sense, I would evaluate myself:
What can I offer my partner in the relationship, what is my biggest needs, are these needs valid and balanced?
My question is, can you live with a certian trait that a person has? If you know yourself well enough you will be able to say if you can cope with it and how long. Can the other person change? Now here is where it gets tricky!
If that person remains in the world, chances are they won't change!!!
At some stage you will want a heatlthy and balanced relationship, where you both give and both receive emotionally. If you have reached your capacity and cannot cope with a negative trait a person has anymore, time to move on - then choose better next time, ask many questions, find out how a person deals with the many aspects of life before you commit.
Relationships will always be complicated, as long as you remain in the world....