Most EZ curls do not fit on bench presses well so be careful or you will lose your front teeth or get your neck broke. Not kidding about the neck thing someone gets strangled or a broken neck each year from mistakes on the bar.
Bottom line your body doesn't give a big rats ass whether or not the bar is bent or straight so if you can get it on your back you can squat with it.
Now, do I think it's a good idea and the answer is no. It's silly! Just use the straight bar it has proven itself as the best way to do the exercises so fix whatever problem you have that is making you want to use an EZ bar.
I am sure if you explain why you are wanting to use it that way someone can help you figure out a way to do it with the correct bar.
I use an EZ bar for deadlifts but not for squats or bench presses. I use it partly because it allows me to get a little more distance off the floor with lighter weight (because I am not yet DLing 45 lb plates on an Oly barbell) and also seems to be easier to grip.
I think it would be dangerous to bench with--it won't fit the safeties. Same goes for squatting--if you need to ditch the bar on a tough set, you run the risk of one side falling off the safety and falling on you--not fun.