Is it permissible to object to someone's leading the prayer (Imamate), or to remove someone from their place in the first row during prayer?

If you meet the conditions for leading the prayer (Imamate) and there is no one among the congregation more deserving than you, then no one has the right to object to your leading. Do not be saddened if you are not put forward; if you are acceptable to the congregation, there is no harm in someone else leading. However, if the congregation genuinely dislikes your leading, you should not lead them, as a severe warning has been issued regarding this. The Prophet (peace be upon him) said: "Three whose prayers do not ascend beyond their ears: ... and a leader of a people while they dislike him."

As for someone pulling you out of the row to take your place, this is not permissible, because whoever precedes to a place has a greater right to it. Some scholars have cited the hadiths of Ubayy ibn Ka'b and Qays ibn Abbad as evidence for the permissibility of a more virtuous person deferring to a less virtuous one. However, the more accurate opinion is that it is not permissible, based on the hadith: "None of you should make a man stand up from his seat and then sit in it." Whoever precedes to a permissible place has a greater right to it, and it is forbidden for others to make him stand up.