Is it permissible to take a percentage of the profits of a company established in my name, while bearing all legal consequences, and are the usurious transactions resulting from that considered permissible?

May Allah reward you for your eagerness to help this person. However, the help must be provided in a Sharia-compliant way. Your allowing him to work under your name is considered aiding him in usury (riba), which is a great sin. Moreover, it involves deceiving and defrauding people, and the Prophet (peace be upon him) said: "Whoever cheats is not one of us." It is also impermissible for you to take a percentage from him in exchange for him working under your name, as this is akin to a guarantee, and it is not permissible to take financial compensation for it. We advise you to prevent him from entering into new contracts under the name of this company and to revoke the power of attorney granted to him, and to urge him to fulfill his obligations and debts.