Enhancement: Besides different shapes and basic line, insert "curve" and "free transform line" should be available in notebookbar item.
I disagree, at least in respect to the contextual sections. Those functions are better located at the sidebar, IMHO. But since the Notebookbar aims to be a control with variable configurations your proposal might be relevant for one of the other setups.
Since there are shapes such as "smile faces", "sun", "cloud", I don't find it too difficult to add curve and free form line as new items. Specially because the last two (curve and free form line) are the most basic type of drawings you need very often (in comparison to "sun" and "cloud" drawings which I didn't use since its introduction).
Sure, curves are simple and useful objects. But shapes in general have to be controlled from the sidebar, IMHO. However, there might be some workflows where shapes in the toolbar, with a collapsed sidebar for instance, make sense.
Yes all the shape functions available in the Drawing toolbar, should be available in a group and the group should be identical across apps, as presently they arent. e.g. Writer has freeform line but no Curve, Impress doesnt have Connectors, Calc has nothing group.
thanks for the bug report. I synced the tabbed notebookbars for the different apps, so in general not only the shape layout is in all apps the same (if the functionality is available) also the other contextual tabbs are synced (draw, image, media, ...)