“תפסת מרובה לא תפסת just means….”
while you are right, the concept is found elsewhere see Gittin 56b
http://hebrewbooks.org/shas.aspx?mesechta=19&daf=56b&format=pdf
regarding Rav Yochanan not askign for the Beis Hamikdosh to be spared (I though the phrase tafsta meruba appears there but it doesnt, though the idea is similar).
I am certian it is used in other sources the way it is used here (though cant think of any). And obviosuly in (our) everyday language it is used