Saving maps online, sharing and collaboration is definitely something I'd like to add in the future.
But if I want to keep the offline editing capability (and I really do) these features are not trivial to implement. Synchronization and conflict resolution hell awaits...
You can press INS to create a new node. Basically, most actions are accessible via the keyboard. Just hover over the toolbar buttons, the hint text contains the shortcut.
edit: As pointed out there are no INS keys on macbooks. Will change this to TAB key ASAP.
The shortcuts TAB and SHIFT+TAB make total sense (Why didn't I think of this?). Will push an update tomorrow with those features added.