i think we are not arsenal, so we can't let accomplished, polished, tactically brilliant player leave so that our la massiah potentially world-beaters-currently raw products can have a spot in the lineup. Well, in here i guess all those adamas', and deulofues' will have to slowly take over.
Plus if you take pedro out and put in new players like reus, etc etc. there are two immediate consequences. One you are changing the natural games of those players who you see in other teams and fancy, which only means, in longer run people will bombarding their forum threads with criticism and critique. example: alexis sanches. He was a monster then, and a perfect fit, sell, all those sell villa shouts and buy alexis have now changed to sell alexis and buy this and that.
Now second is most important. Barcelona as a team will lose its identity. Unless we want to be real madrid, we have to stick with technically gifted players, who have great visions, tactical ability, ability to play football with and without the ball, movements , tiki-taka's and one two.
Now since we high possession game, almost 70 mins of the total 90, we stay in opposition half, which makes us defensively vulnerable. Moreover our absolute first teamsers like messi, iniesta, if neymar, just can't defend to great extend. And a major reason for that is most of the time when we are hit with attack they are too up to comeback.
Now another point is, we are a team, with an average height of 5.7-.58 And plus are fullback like go to forward (now this is tactically compulsory), you don't want fullbacks to sit at back when you have the ball 70 mins in the game. So you need extra men up front.
Now from defensive point of view we are weak, on the counter, plus if there is a good crosser, any team will have more players to head the ball in the goal, then the player we will have to defend it away.Which leaves it again absolutely vital for us to press and press hard right from the front.
All of these factors combine and make is absolutely mandatory for us of have players like Pedro and Alexis, especially on the wing side of the forward line. Who can track back and have great one-two and movements. Plus they can give us 15 plus goals per season aswell.
Now i think, the only problem we have is our system has been very successful in the past, but now teams know, how we play. Our possession and stretched wings don't give us crossing possibility as we don't have a tall no 9. Now even if we had one, having just one, makes it more of a gamble than a plan b.
Normally teams have multiple system within a squad, to entertain the skills and abilities of individuals, when lineup changes, their approach changes slightly and tactically orientation becomes somewhat unpredictable, and unsystematic. I think we have been playing systematically since ages. With some standard strengths and weaknesses. Now this tiki-taka possession based system is what we are proud of. So even i don't want it to change. Now for that, we need absolutely right kind of players. And then we can have them have their freedom, and adopt the system slightly to their skills and characteristics, but the primary tiki taka has to stay intact.
Now what i have proposed in the past, in this forum is , either messi has to drop a bit more deeper, to see the ball from deeper positions, and a classical no 9 with two pedro and alexis on sides (neymar will do exceptionally well in no 9(tello as sub) (neymar then can occasionally change to false 9 as a surpise and messi can attack those spaces created by neymar movements). Messi in this case will then be much more effective choosing between three front line players to pass. And if will make him more mobile, free to go anywhere and effective as well. his runs will be much more unpredictable, and he will be a classical no 10 instead of false no 9. Now this doesn't have to be match in - match out strategy, someone with the profile of rafinha can take that role and messi can stay in his usual role.
Man oh man, would love to see Pedro vs Alves...believe me, Alves wouldn't come up on top in that matchup 
