Nah, if it's gonna creep it'll find a way. Usually over something you don't want it creeping over.
I would think you are probably right about the first one being hedge nettle. I have guara too which is why I knew after looking again that is wasn't that. Mine is just starting to set buds. I will take some pics of it when it opens. My brain gets a little fuzzy on what plants look like after a year of not seeing them.
Is it possible it is one of the many varieties of wild flowers that are out there?