Can family members apply along with me? Everyone need their own copies of records?

Hello! I am at the start of my journey toward Croatia citizenship. There is a lot of information sources out there and I'm finding some of it to be a bit overwhelming and often inconsistent. If anyone can point to clear resources and/or answer these questions succinctly, I would appreciate it.

By way of background, I would be applying under Article 11, citizenship by descent. I recently identified my great-grandmother's birth record from 1905 in the Kordun. I have not requested an official copy yet. I'm also working on obtaining the records in between (grandmother and mother, both born in the U.S.). I was born in the U.S. and live in Western New York, so my appointment would be through the New York consulate

1. My wife (who has no Croatian background) and two adult children in their 20s are also interested. Do I need to go through the whole process first, and only then would they apply (as a spouse and as descendents of someone with Croatian citizenship), or is there a way to streamline the process both in terms of duration and paperwork? In other words, can a spouse or adult children "piggyback" on my application?

2. Should I be requesting multiple official copies of the 1905 Croatian birth record from the archives in anticipation of my other family members needing it later? From what I've read, these would not expire.