in Vim, if I yank a word, I can paste the resulting register contents in the command line by typing ctrl+r ". To me this would be useful if I am using the command line to run an external file that isn't the default behavior.
You can use %r<reg-name> macro. It will be expanded properly. There is no direct equivalent to Vim's Ctrl+R. It's not hard to implement one, but given that it's a list of files, each of which needs proper escaping, this task is left on macros as of now (the disadvantage is that you can't edit the list directly).
%r<reg-name>