>>14-15
質問スレ荒らすなｳﾞｫｹ

>>13
Finderから「ほかを隠す」もしくはoption+command+H。

いちいちFinderに切り替える手間が惜しければ、
↓のAppleScriptをメニューに入れておけば一発。

tell application "Finder"
activate
set visible of every process whose visible is true and name is not "Finder" to false
if the (count of windows) is not 0 then
set collapsed of every window to true
end if
end tell