For me, it's not a question of "being Barca" - we couldn't if we tried. Without Messi, Barca wouldn't be Barca. Without Xavi and Iniesta, Barca wouldn't be Barca. They might play a similar style, but there would be important differences.
There's some great stuff here about tactics, but some of the posts about how the academy plays really got me thinking that personnel is a massive factor in how you approach the game.
The sort of intelligent, skillful players, who can move the ball around in neat triangles, spot the right pass and skip past the opposition, are very rarely also blessed with the kind of determination of the willing-to-break-legs-to-win-a-ball, constantly pressing style seen in most Premiership midfielders. Remember Alonso, one of the most skillful passers ever to grace the club, felt that tackling was not a skill, but an attempt to correct a mistake. That's a fundamentally different approach to 90% of players in this country. It's worth noting that Rafa paired him up with very differently-minded partners in Sissoko and Mascherano.
For me, the club should be looking at possession and movement to control games where possible, but also pace and ball-winning, to spring counter-attacks. A lot of the sides we play tend to sit back and "park the bus" and they do it very well. Adaptability is the key. One player moving forwards always to be covered by another. Draw teams out and get the ball back when it is most useful, not just as quick as you can. There can be a great advantage to letting the opposition get forward in numbers when you are confident you can stop them from scoring. If they've left themselves open at the back, and teams who defend in numbers usually will do when they get a scent of goal, then the interception needs to be made with precision and speed, and the charge forward has to happen before they even know they've lost the ball.
That's why intelligent players like Alonso or Lucas are so important, and it's something that isn't always obvious when watching the game. The supporters will demand that players run hell-for-leather after the ball and "get involved", that everyone pushes forwards to "attack attack attack" of course they do, they want a goal and you score goals by attacking. But goals can come without massive pressure and build-up, too.
Alan Hansen has often suggested that all goals are essentially down to defensive errors. So how do you increase the chances of an error for your opponent? Either you put him under pressure with sustained attacks, which puts him on guard but gives you more opportunities for him to make the mistake, or you draw him out, lull him into a mis-reading of the game or a moment of over-confidence. Both methods work, and which is more effective will depend on who you are playing. Doing both at once is very difficult indeed.
The club seems set on developing more first team players through the Academy. It's a noble goal, and the work is being done, although my suspicion is that we'll still be signing a lot of players from outside, too. The vital thing isn't that the lads play the same formation as the first team, tactics in football evolve all the time, teaching a fifteen year old a rigid system of play that will be out of date before he makes his debut isn't particularly useful. What is important is that they learn the underlying philosophies of the game, and of the club. That they learn the skills and develop the vision that will allow them to flourish as successful footballers, regardless of the formation they are asked to play.