How can I add a new or custom toolbar in LibreOffice?

Question

There is the so-called "Quick Access toolbar" (link to its Microsoft's Excel help page for it) in Microsoft Office products available. It consists of little icons for the included functions.

1. Can the same–or at least similar–toolbar be created for LibreOffice Calc?
2. Could it be done that the toolbar would automatically assign shortcuts to the functions which are included in said toolbar, e.g. like for a pre-defined hotkey? (MS products use ALT + i where i is incremented for each entry.)

Answer 1

Can the same–or at least similar–toolbar be created for LibreOffice Calc?

Yes. Instructions below.

2. Create a New Menu or Toolbar

Open Tools > Customize and select the tab for the kind of menu or toolbar you want to add. Once selected, click the hamburger (three horizontal lines) icon. You should see it beside the Target drop-down menu. Pick Add from the options.

Give your new menu or toolbar a name, then open the hamburger menu again. Choose whether your menu should display Icon and Text, Icon Only, or Text Only. Text options will display the tool's name.

After that, you can begin adding options using the arrow functions. Your new menu or toolbar will appear right away when you're done.

Source: 3 Ways to Customize Menus and Toolbars in LibreOffice