the basic translation or interpretation of Quran would be the same whomsoever does it. However, the verses which draws line between sects need to be understood by someone who gets knowledge from Allah, someone Allah talks to. Once someone claims thats hes sent from Allah (Imam Mahdi AS, as you’re waiting for)..and He interprets the verses and tell the Muslim ummah the meaning of it, there should not be any doubt in any one’s mind that it can be wrong. Sure, it can be challenged..but the mere challenging of those verses should not be a hint of it being right or wrong. They should actually be challenged and proven wrong.
Aalim or someone from Allah. It is up to us to know wat to follow.
One should understand the role of Khalifa first. The role of Khilaafat is to carry forward the message given to a prophet, spreading the word.. and following the footstep of the prophet of whom they’re Khalifa of. A Khalifa would not interpret Quran and have a different understanding of it than the prophet did.
A student will always follow the method of his teacher..and ofcourse teacher has to be right or else he wouldnt be a teacher in the first place. A student can make mistake, but he tries not to because he knows the method/answer of his teacher.