Sub item improvements, permissions improvement and saved views (tabs) improvements

My main table is very busy as I use the ability to hide columns in certain views to discuss different topics with different groups. HOWEVER, you cannot hide subitem columns.
1- Be able to hide sub item columns from a view
2- Be able to, when making a subitem, copy the columns of the main item automatically. I have to manually add each column to match the main item so that when converting to and from subitems I don’t lose information. However all these columns are then visible.
3- Be able to ‘search’ in subitems. At present the search function doesn’t search within subitems making them very difficult to use.
4- If I expand subitems, or certain subitems, to be able to save that as the view so I don’t have to constantly open them all.
5- To be able to save a view with certain groups collapsed so that when I return to the board those groups stay collapsed.

6- We have large group membership for boards. I however want only certain members to view the entire board, and to restrict members to only see certain ‘views’/tabs at the top. i.e. be able to invite people just to the tabs/views I want them to see. At present it bamboozles people with so many tabs and views and isn’t appropriate for most staff to view all of the information on the board. So not restricted their view of individual items, but restricting their view to a certain saved ‘view’/tab.

7- To be able to drag the tabs/saved views around. The ‘favourite’ idea makes it very difficult to get them in a suitable order. I also can’t control the order of the tabs/saved views that the other members see. I need to be able to control the view they get of the board more.

I would also like to be able to hide subitem columns from a view.