Some of my college applications would benefit from switching the common app essay, in my opinion for another essay I already have written. Can you switch/edit essays on the Common App as many times as you want?
Yes you can.
If you want to submit different essays to every college, just change it before submitting each college’s application. And make sure to check the preview of you application before submitting (common-app will provide you a preview before submitting) to see if you have the right essay for the college your submitting.