Is it preferable to renew the marriage contract due to the presence of a witness who is an innovator (follower of bid‘ah) whose innovation does not amount to disbelief, knowing that the husband has not yet consummated the marriage with his wife, and is it possible to send a new witness to ask the guardian if he married his daughter a week ago?

Justice is a prerequisite for a witness, which means refraining from major sins and mostly abandoning minor sins. It is not a condition for a just person to be free from innovations (bid'ah), unless these innovations are a cause for disbelief. Thus, "the testimony of an innovator whom we do not declare a disbeliever is accepted." If the third witness is just, the matter is clear. Otherwise, the contract is valid with the testimony of a just innovator whose innovation is not a cause for disbelief, and there is no need to re-do the contract.