With this script you can paste a single node to a selection of nodes just with one click.

It has some limitations, though. Only one node can be pasted and after pasted, if you want to keep the node graph tidy, you must select all the new pasted nodes and press L.

Here it is:

def superPasteSingle():

    nodeList = []
    for s in nuke.selectedNodes():
        n = s['name'].value()
        nodeList.append(n)
    maxItemNumber = len(nodeList)
    itemNumber = 0
    while (itemNumber < maxItemNumber):
        nuke.nodePaste('%clipboard%')
        new_node = nuke.selectedNode()
        new_node.setInput(0, None)
        connect_to = nuke.toNode(nodeList[itemNumber])
        new_node.connectInput(0, connect_to)
        itemNumber = itemNumber + 1