Since I used to be a nurse I am on home territory for some of this article (and I used to live in HK!)
1) I am guessing that this is 'brought out' not 'bought out', a phrasal verb. It means that the challenges of the situation appeared, and they seem to be more difficult to manage than the idea of climbing a mountain.
2) 'to call something off' = to cancel something'; and here the writer feels the son might choose not to be part of the relationship, in the way that a 4 year old child might react.
3) 'goo-goo' - an expression to refer to the way babies sound before they start to formulate words. The expression gives the impression that everything about babies is easy and soft and nice.
4)Health Visitor - a health professional who has a community responsibility after mothers leave the care of midwives, 10-14 days after giving birth
5) Gastric feeding - a method of giving nutrition directly to the stomach using a tube and liquid nutrition, if a person can't eat in the normal way.
6) 'Like-minded people' - people who have similar attitudes or opinions to the writer.