if you are in a relationship with someone, it is right to ask someone else for advice? considering they only know your part of story, and it could be unfair for your partner?

It can be unfair because they don't understand both sides of the story but it can also give you understanding in other situations. They can give you the courage to further understand the situation. Perhaps if the other person can also help you understand both sides of the story. Therefore the answer may not be as bias. Bias answers can further inflate the situation. I think it is best to ask for complete honesty on the situation. Try talking to someone you can trust because then they can perhaps understand both sides of the coin. By being truthful to both sides it can become easier to understand .

I think it is fair, because you ultimately have the choice about whether to follow that advice. You have enough information to complete the picture. But sometimes people can offer us a new, outside perspective that we couldn't see. But the key is to look at it as perspective rather than advice. You have to make your own choices based on what feels right to you after you've weighed all the information. :)

It depends on who the person is. However, an advice based on partial information could not be the better advice to follow. Because they made suggestion on what they know and what they understood. It would be like a taking cough syrup for fever. So, could be better if the suggestion or advice based on full information so that you could have a clear view of potential outcomes from following the advice.

No, it would not be wise to ask anyone for advice. Sometimes no advice is best. When you start giving advice and, you do not know the whole story, it can be a really bad idea. You might have good intentions of helping but, you might do more harm than good. It is best to leave advice given to those with professional training, and those who have the training and the schooling to give advice. The only person, who knows your situation is you. I am not sure. It all depends. My question to you is this, "Do you trust the person, and know the person well enough to give sound and harmless advice?" That is the question, only you can answer.