Is it permissible to ask God for protection from major sins and from Satan, the accursed, or is that considered an transgression in supplication?

It is permissible for a Muslim to supplicate to Allah Almighty to preserve him from grave sins and misdeeds, and there is no transgression or violation in that; because it is a permissible preservation for believers, not the obligatory infallibility of prophets. It has been reported in the prophetic Sunnah (definition) that the Prophet, peace and blessings be upon him, said: "O Allah, preserve me from the accursed Satan" when leaving the mosque. And it is narrated from Umar, may Allah be pleased with him, that he used to say: "O Allah, preserve me by Your rope." Some scholars have held that the proper etiquette is to ask for protection for ourselves, not infallibility, and this might be what is intended in such supplications.