Here is a video proposal :
Tell me what you think
Partial solution (adding reroutes to all unused inputs and replacing them) :
If you prefer to read or didn't understand this rushed video :
So you have a bunch of nodes and you want to add reroutes to their inputs
Voilà. Now you can replace those reroutes by any node with Shift+S. And if you need them to have specific parameters, don't forget Right-click > "copy to selected" to apply your changes from the active node to all the selected ones.
I believe if you select the nodes and hit F would connect them. I do not know what would happen if you connect with all the boxes selected.