Children

Edit: There is a narration that says, "When a believer [in heaven] wants a child, Allah will created him or her without pregnancy or birth in whatever form [his parent] wishes, just as He created Adam." (al-Ihtijaj, 2/130, ascribed to a letter from Imam al-Mahdi (A))

I am not sure what else is mentioned on this subject in our sources (perhaps someone can add something.). 

However, possibly they will not want to have children there because often our desire to have children in this world is affected by hormones or society, or the desire to procreate is put into our hearts through divine mechanisms to carry out the plan of God for humanity.

God knows best!

I agree with the viewpoint that you said regarding Imam Ali (A) loving his wife greatly, and it seems that the Prophet (S) and his family had very open hearts, and also that love for their families was part of their spirituality and perfection. So I would not say that, in the tradition ascribed to them (A), there is an ideal of cutting of love for one's wife and children.

As I am sure you know, there some clear narrations on this topic attributed to the Prophet (S) such as "I was made to love three things - perfume, women, and prayer", and as related from Imam Kazim (A) "whenever a man's faith increases, his love of women increases." Of course this should not be a haraam love whereby one does illict acts in the name of love, but, rather, the capacity for love and connection with and appreciation of the opposite gender increases, perhaps as part of spiritual growth. It is not a sign of spiritual growth to be cold and standoffish with one's lawful spouse (unless there are serious marital or personal problems that cause that, unrelated to this subject).

Of course, there are many approaches to mysticism and gnosis, and sometimes people prescribe other approaches according to their understanding for their own reasons even if the are somewhat different from the above.

However, perhaps one can glean from the Qur'an and hadith that (a) although it is good to be open to one's spouse and children and love them, one should not grow overattached to them to the point where they place them above Allah, whatever that means to a person in practice, (b) one should not be attached to the worldly life, although one can take comfort in the knowledge that human relationships can outlast the worldly life, and (c) sometimes we are tested by these things, and we are also tested by what we love most. For some people, their greatest tests in life relate to their family or children. Inshallah you will be protected from this. 

In my view - and this is just my view, it may irk others - in some Muslim spiritual circles there is a sort of cynicism when it comes to human love, and an emphasis that this world is just for tasting the delights of Allah or the hereafter, and we should not dwell on these things or expect to have them. I have often suspected that this may be rooted in some of the social restrictions and disappointments relating to worldly life that some people have had, especially in the older generations - for instance, feeling compelled to marry someone who one didn't really want to be with, or other such problems. And to some degree, a way to deal with this is to look to what is beyond this world spiritually and not focus on it. I am not saying this is the situation with everyone but perhaps it is a factor.