At what point should you start to play mainlines.
I think there's no hard rule here, but if you're ambitious, the sooner the better 
Usually, beginners don't start right away with mainlines because they're a bit complex to handle, but working with mainlines can only help you develop your chess skills.
Your only goal in the opening is to reach a playable middlegame .
Very true. This is a saying of the great Lajos Portisch, which was also expessed in a slightly different style by Harry Golombek.
As big of a opening fan I am I still agree with this I only study opening untill i know I can reach a flexable/playable middlegame
Your only goal in the opening is to reach a playable middlegame .
Very true. This is a saying of the great Lajos Portisch, which was also expessed in a slightly different style by Harry Golombek.
As big of a opening fan I am I still agree with this I only study opening untill i know I can reach a flexable/playable middlegame
I wish I could've been a opening fan too... since the many openings and their countless variations allow to make too much mistakes as a beginner. Openings are worrying me the most because I don't understand the logic behind many moves and replies (except for popular easy e4 openings).
More reason to jump on that diamond membership, TheCabal. IM's David Pruess and Danny Rensch have recently released beginner videos on openings. IM Pruess shows the virtue of each and every first move possible and IM Rensch bravely does a survey of all the major openings. GM Kaidanov has a video on "how to develop an opening repetoire" that also surveys the major openings, but from the perspective of what is appropriate for your personality type. Great stuff-all of it.
Mainline openings are fine for OTB chess at regular time controls, and also for correspondence chess. But if you want to actually practice your openings. Over and over again, at G/10 to G/60 speed, you probably need a "narrow repetoire."
If you still insist on playing "mainline openings" with white, then use Tony Kosten, "The Dynamic English" (1999, and only @150 pages) against everything black plays. And buy yourself a couple "repetorie books" for the black side.
"Study brings wisdom, practice brings perfection," Johann Hellsten, Mastering Chess Strategy, (2010). This book arguably contains all the (thematic) "tactics" you will ever need for the middlegame.
Buy you yourself some good books on the endgame, by James Howell, John Nunn, or Jeremy Silman. Study them systematically. Then "you're done" with the study time you need to reach USCF A Class or higher.
But if you don't narrow your openings, then every game is still "an adventure." And you are not getting the "thematic practice" and "thematic middlegames" you will obtain from playing a more narrow repetorie.
But if you don't have a life outside of chess. Then of course, play "the mainlines." More power to you. And plan to hire a chess coach to help you through the opening maze, and the maze of "thematic middlegames" you will inevitably obtain.
Indeed, "Every Game An Adventure." There is a bridge bidding system with roughly the same name.
At what point should you start to play mainlines. I always played mainlines as Black, but had a narrow repertoire. My White repertoire consisted of sidelines which initially served me well. I then reached a point where the stronger players were equalizing without effort when I was White. I agree that you shouldn't expect your openings to win games for you, but I think you need to pose enough opening problems to wear your opponent down some, and at least be able to play for a win even if he replies correctly.