Good and not so easy questions.
Do not take my answers for granted, do more research.
Junipers do loose needles. Typically these are the 3 or 4 year old needles, but this varies per spedcies; read more about the life cycle here:
awaytogarden.com/when-inner-conifer-need...urn-yellow-or-brown/
Hinoki Juniper will not bud back on old wood, so you must make sure you always leave foliage on a branch that you want to keep.
Pinch only the fresh new growth (the foliage tips). Do NOT completely remove all the new growth - it will weaken the tree.
If you need to remove a long shoot, use scissors and cut it off at the base.
And do research. There are many good resources, giving you more and better information, from people that have experience with hinoki cypress.
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