i read that you shouldnt keep any cheese out of refrigeration for more than 2-4 hours. i left some cream cheese out (unopened) for 2 hours to soften it to make cheesecake, but it was still fairly hard (it's in the 50s in my apt). i really couldnt make it smooth, so my cheesecake was fairly lumpy. can i leave it out overnight like i do with butter?

It would probably be fine, but there's no real reason to. You could soften it in the microwave or cut it into smaller pieces and leave it out. More surface area = faster defrost time. If you do that it shouldn't take more than 2-3 hours to soften.

this, and ill add that if your apt is in the 50's then its even less worrisome to leave it out.