Hi @R.B
The answers for now are no, no & no.
For column width the initial setting is based on the width of the longest cell value for the column. You can then as a user resize the columns via dragging and this be stored and will persist for the duration of your session so if you leave the screen and come back then you will still have the resized column.
Setting a sub-view to read-only is an interesting one. This isn’t currently supported but might be a good feature. What’s the use case?