How can I change the view options for all subfolders at once?
One option is to use the Set Folder Views action in Automator:



There's no way to change the size or position of windows though.

You could also use a script like this, but it's just as slow Automator when applying window properties is checked.

tell application "Finder"
    folders of entire contents of (POSIX file "/Users/username/Folder/" as alias)
    repeat with f in result
        open contents of f
        tell Finder window 1
            set toolbar visible to false
            set sidebar width to 0
            set statusbar visible to false
            set current view to column view
            set bounds to {474, 250, 1318, 750}
            tell its column view options
                set shows icon to false
            end tell
            close
        end tell
    end repeat
end tell


Use as Defaults applies to all normal folders, but folders that have been opened before have .DS_Store files which can override some of the defaults. You could also delete the .DS_Store files:

find ~/Folder -name .DS_Store -delete
osascript -e 'quit app "Finder"'


It also removes Spotlight comments. Once you change some view options or the sorting modes, they are saved to a .DS_Store file which overrides the defaults again.