Do I really need to study openings ?

as a poor player (just look at my rating) but who has years of correspondence chess under my belt, I think that openings are important to a point.

1.  You need to understand opening concepts, as putting yourself in a bind on move 5 means you will struggle.  

2.  You need to understand endgames.   Many low rated players have issues even with doing a KR-K ending.  

3.  My biggest weakness is that I am still somewhat blind to attacks on me, and I am still improving my tactics.  

4.  You have to learn to be cruel to yourself and analyze yourself mercilessly.   A computer is good, a expert or master level player at your level might be better. 

5.  With openings, you need to at least identity a solid opening for white that you like, and responses to d4 and e4 as black.  If you know the concepts and say, the first six moves or so you will do well at the low level, and more importantly understand how to break down other players.  In fact, most of the games I won on Chess.com so far at low level has been just chasing the other side's queen around in the opening since players like to bring out the queen early and I get developed while they moved the queen 4 times.   That can make up for blowing tactics, which is my special skill.  

So learn a few openings to the first 6-8 moves, and understand what that opening is trying to do.   At low level I had been able to ride on the Bird train for a long time since I understood what it was trying to do and others didn't.