Creating an Opening Repertoire

Back in October I decided to get serious about chess.  I have made some pretty good progress.  (You can't judge from my rating on Chess.com because I have been mostly playing OBT.  I'm around 12-1300, and it is time to start building an opening Repertoire.  I want a repertoire I can play for the rest of my chess career so I can gain a really deep understanding of it.  But there are things I need answers to first.  It is my current understanding that for White you need to choose, at a minimum 1 Category of openings, either E4, D4, C4, or NF3, and maybe NC3.  And for Black you need a response for each of these moves.  Am I correct in this?

Second, once you choose your category of opening, E4, D4 etc. how many variations should you learn.  I DO NOT want to get bog down into move order hell.  I want to choose an opening repertoire so I can improve my position in the middle game and then focus on my middle and end games while learning more and more about my chosen repertoire as I play more.  I don't want to waste time bouncing from opening to opening.

3rd. All the advice says, you need to figure out your style.  How do you do that?  Is there an easy way to figure this out.  I know I WANT to be more positionally minded, because from position tactics arise, but how do I determine my current strengths?

4th, once I figure out my style of play is there a database that breaks down the major openings into catagories of style so I can easily pick and choose what I will like? 

Thank you for your time.

I wouldn't bother so seriously with the openings at your level, if you see yourself as a serious student with the need to most effectively use your study time.

I say this as someone who whipped up and studied and refined 50 typed pages of repertoire.

Don't get me wrong; I like fiddling with openings but it really made little difference to my improvement as  a player.

it's not a wise investment.

As a mere dabbler, I guess I'll always be attracted to opening study, but it would be wrong for someone whose main aim is to get stronger in an efficient way.

As the masters tend to advise, don't worry on openings until 2000 (or so). The games are won and lost on play well after the opening phase.

Just work on being a player of strong chess.

ALL? THAT IS ABSOLUTELY FALSE. Some Masters may advise that, but some advise to the contrary. I was just reading an article today by respected IM Greg Shahade who advises the exact opposite. He advises, as do many other Masters, to tweak your opening repertoire depending upon your level. Also, I personally know people in the range of 2150-2400+ who do the same.

I would suggest too to study a bit the opening. Maybe trying to refine the lines you play game after game. Keep studying tactics and other things and dont lose too much time only on the opening phase.

About style of play i think that at our rating we dont have a style. Also players around 2000 are severely lacking in tactics, so lets try to always improve our tactical vision. We cant also say that we have a strategic style because what we often play passive/ slow moves. I dont want to talk about endgame tecnique because there we should cry :) let's try to find active moves that pose some multiple treaths first.