First of all, where did you get this idea that learning about Abrahamic religions is a taboo for agnostics? If by that you mean taking lessons from them, then yeah that might be a taboo for irreligious people because the Abrahamic religions have not established themselves as moral authorities. Their bloody history, for irreligious people, make them more of a warning than moral authorities. However, if it is genuine curiosity, then I am not aware of any taboos surrounding that. I personally indulge greatly in learning about the Abrahamic religions' teachings and history because so many people follow these religions. If anything, learning about them makes sense. They are the source of authority for so many people.

However, unlike you, I am convinced that there is no god. I used to be in a similar position. I used to think that there might be a god, or a supreme being of some kind. I used to even pray to him by calling "the god" or "my god." I refrained from using words like "Allah." Then I read about the history of belief in human societies from pre-civilization human societies to the present day and that destroyed the idea of god for me. Reading about that history shows you how the idea of god originated as an idea of a supreme being with great powers. This supreme being slowly begins to turn into a god. Then that god becomes multiple gods with special characteristics and powers. What's interesting is that these gods have very human personalities. The multiple gods slowly turn into a single god, and that's where we are today with the Abrahamic faiths. Reading about this destroyed the legitimacy of "god" for me. The history of belief suggests that the idea of god served social purposes and was initially invented by human societies to answer questions about existence. Also, many prophets who claimed to have received a revelation actually borrowed ideas from religions and beliefs that predated them. I'm not aware of any prophet who came up with something revolutionary and original. Many important concepts such as the supreme being, the afterlife, rituals, and rites which are the foundation of almost all religions practiced today, were present in pre-civilization human societies. For me, reading about the history of belief in human societies stripped all the legitimacy from the idea "god."