LibreOffice

• You can insert new rows or columns by Highlighting a row or columns and pressing Ctrl+Shift+=
• Contrary to the advice I first read, you can move a row or column by highlighting it, holding Alt, then grabbing and dragging a cell from the row/column.

You can customise the right-click/context menus via: Tools → Customise… → Context Menus

I've found it useful to add my own styles to this list, for example (Select 'Styles' from the 'Category' drop-down to get more options).

You can customise keyboard shortcuts via: Tools → Customise… → Keyboard. I've had issues with Calc settigns not overriding LibreOffice ones, but it's still useful. Made it easier to paste unformatted text, for example.

You can and and remove things from the autocorrect by: Tools → AutoCOrrect Options… I've found it a bit aggressive, so mostly disabled it, but you maybe want to add some combinations of characters to be transformed into symbols.