Is a person's fear of committing sins and avoidance of places of corruption, out of fear of a bad end, and his preference for staying at home for worship, considered a bad assumption about Allah?

You are right to shun places of corruption and to fear a bad ending, and this does not contradict having a good opinion of Allah, because having a good opinion necessitates good deeds. Among the things that help achieve a good ending are steadfastness in obeying Allah and constant remembrance of Him. A bad ending has causes such as: excessive devotion to worldly matters, turning away from the Hereafter, and persistence in sin. Sleeping early is a good thing, especially if it is to aid in performing night prayers (Qiyam al-Layl) and Fajr prayer, and staying up late is disliked except for a legitimate Sharia purpose. One should also seek recreation in places far from forbidden things to refresh the soul.