I think the group node needs options to change the socket types. For example if you want to create an empty group, you’ll need the ability to change from the default socket type, for example if you want to change from a slider to an image input.
At the moment you have to delete existing inputs, create a new node inside the group that has the input type you want, and then temporarily connect that to a new input before deleting it.
A better option would be a dropdown inside the group node’s item tab, that lets you select the type of an existing socket.
And I think that Group Input node could be more useful.
Currently, user can create several Group Input nodes to make small local connections to outside of group.
That keeps nodetree inside group clean, without the need of long connections all pointing to a unique Group Input node.
But it is a pity not to use this ability to create a subpanel.
Imagine only for this node, under the Name and Label field, a Sub-panel Label field.
User would just have to give a label to group input node to create a sub-panel in summary of nodegroup.
That sub-panel would be placed under settings connected to Group Input nodes without labels.
And when multiple sub-panels would be created, they will be ordered according to their name.
A sub-panel, labelled “Images”, corresponding to node “Group Input” would be followed by a sub-panel, labelled “Location”, corresponding to node “Group Input.001” .
This last one would be followed by subpanel “Rotation” corresponding to “Group Input.002”, etc…