I agree with this four point you have stated,I believe with is it will help alot at least to know some few things about to the person you want to work with..
Firstly I will say if the person can not add value to you then is not worthy of being a friend..
Trust infact as for me if someone can not trust me I can't continue to move with the person as a friend not to talk of me not trusting the person trust is really very important in relationships
Great one "understanding"were their is no understanding their will always be fight and dispute among each other because a little words might be taken for a different meaning which might cause alot issues.