Can a Muslim be strong in one aspect and weak in another, such as being weak in speaking classical Arabic for fear of people's ridicule, yet strong in studying and seeking knowledge, and wanting to benefit Muslims?

It is from God's mercy that He diversified the paths of good. A Muslim should adhere to the door of good that has been opened for him and strive for accuracy and closeness in other matters. His inability to master classical Arabic (Fus'ha) does not diminish the perfection of his faith. However, he should strive to learn it to master it, so that it may help him understand the Book of Allah and the Sunnah of His Messenger. He should also pray to Allah for success in compensating for any deficiency he may have.