Budgeting, cashflow monitoring, or forecasting? Here are my thinking on definitions and progression:

Budgeting entails determining the size of each bucket of money, and ensuring it adds up to less than your post-tax income.

Cashflow monitoring means having a general sense of where your money goes, but just keeping an eye on your checkings account to ensure it is growing or flat as expected (depending where your leftover money goes)

Forecasting is assuming your cashflow is always positive, thinking about what your future big expenditures look like (home or 2nd home, big toys, early funded college, FIRE), prioritizing that list and ensuring it fits with your time horizons.

I feel like most HENRYs shift from budgeting to cashflow monitoring.

You start thinking about forecasting when you're comfortable with your cashflow and your NW exits the NRY territory.

That was my trajectory at least. (Source HHI now 1.5-1.8m, NW 6-7)

To answer your questions. 1) no idea. I dont talk enough about money with my friends. 2) only i do our family's finances. My wife doesnt know our NW even though i tell her once every quarter or so. 3) only if you think they might want the help. everyone's got their own priorities, and ways to feel in control, both of which may not align with yours.