Re: sikh teaching/ community & links to Hindu tradition
First there is no such thing as "Sikh teaching," it is Guru's teaching. Secondly, the teaching is Timeless and Universal and so obviously no you don't need to have understanding of Hindu tradition. If it was the case that you need to have understanding of Hindu tradition to have real grasp of Guru Sahib's teachings, then you would not find Gurduaras in the likes of places like Iran, Iraq, and Afghanistan where the prevalent tradition is of Abrahamic origin, and where Guru Nanak Dev Ji had also spread the message of Ik Oankar.
Yes, for those completely uneducated people about Eastern society and religions, it would be helpful to understand some of the basic background information as to what was going on in the time period when Guru Sahib was spreading Vaheguru's message, but its not absolutely necessary just because the message is so Universal. Gurbani is so eloquent that it is timeless, as it applies to not just the time period in which it was written but for any time; so it should be as it is Vaheguru's Shabad.
