Is it permissible for the one being led in prayer (ma'mum) to precede the Imam in rising from prostration, or must he wait until the Imam rises before he does?

If the Imam pronounces the Takbir when rising from prostration, this is prescribed, and it is recommended that his Takbir ends when he stands upright.

It is not permissible for the congregant (Ma'mum) to precede his Imam in any pillar of the prayer, due to the Prophet's (peace and blessings be upon him) prohibition of that and his warning to those who do so. Whoever precedes his Imam intentionally, knowing the prohibition, his prayer is invalid according to the most correct opinion, or valid with sin.

If one precedes the Imam out of forgetfulness, his prayer is not invalidated, but he should delay himself by the amount he preceded the Imam.