The ability to edit/delete nodes makes the management of more complex flows so much clearer, especially as flows structures change overtime.
I've accidentally created Dynamic Content nodes many times in the past and the only way for me to get rid of them is by recreating the Flow. This is fine when it's being built. However, when a dynamic content node is accidentally created later, recreating the Flow isn't an option. Having a way to edit/rename them would be very beneficial.
Yes, this is a major pain. I'm sure they stick around so every flow call does not crash when a node drops off, but a manual way to get rid of them is needed. Like @ghrimm says, its a pain. Especially when you have to add a new call to the flow, and you have to put values in for nodes that have absolutely no use.
I just tried Save As and even export/import but it still wont let go of unused nodes.
I dug into the export files. the file definition.json contains some vauguely distinguishable references to the nodes. Even if I knew what I was doing, I would refrain from editing it. But, if someone wanted to venture into that realm, it looks like it could be possible.... but, highly risky.