Maybe after they start agreeing (if Barcelona's offer is successful) Will Lewa be willing to take a pay cut too? because for the current season conditions like this are mandatory for Barcelona in order to secure their finances so they don't fall for too long.
It's still two possibilities considering Lewa doesn't want to be at Bayern one of the reasons is asking for an extra salary there and when he wants to be at Barcelona this obviously has to be discussed. Don't let them have a deal but are still hampered in terms of salary.
Schematically I wouldn't really worry too much about him, he's the spearhead up front and Tiki-taka prefers midfield and wingers so he just needs to adapt a little bit up attack.
This is rumor only, we have to wait for final deal and announcememt of the transfer. Lewandowski is not happy in Bayern but will he agree to sign a contract with Barcelona is different. There are more big clubs in Europe can give him a striker position and with better salary than Barcelona.
In other clubs, he won't have to change his playing style and struggle with tiki taka. We know old people, old players are more difficult to adapt to new things, new tactics.
If he agrees with Barcelona, moves there, he will have to face with one of biggest challenge in his career, adapting to a tactic he has never played with, tiki taka