Ineed pronouncing đ/đ correctly, i constantly mess it up. any serbo-croatian speakers, students, teachers that can ?

It's just like a 'd' as in 'schedule'.

'dž' (because you might have problems distinguishing them) sounds more like a 'j' as in 'just', but it's tougher :))

if skull joint were movable then they can lead to shearing of brain layers and cause brain damage.

nobody knows everything, but parents are normally more experienced than their children based off of worldly experience despite the fact that a child might think that they know better than their parent in any given situation this might just be caused by ignorance and lack of experience.