Deleting all footnotes could be done with a regular expression and find&replace. I think this would work:
Find: regex:\\f.*?\\f\*
Replace: blank
As with any global find&replace, you would want to save a point in project history before doing this and check carefully afterward that it didn’t have any unintended consequences.
I’m pretty sure the answer to importing footnotes from one project to another automatically is a solid ‘no’, but it’s possible I’m wrong on that. One significant issue is that footnotes are tied to a word or phrase, and that wouldn’t be present in the other project.