Sikh80 ji,
Please don't jump to the conclusion that you have committed a sin. And anyone is free to post from vedantic sites. You said "Maybe there is a communication gap?" Maybe I was too hard on you. You have a tender soul.
My point is only that clarification is needed when the naam jap is inspired by a human who is regarded as a Satgur. In Sikhi naam jap is inspired by the shabd of Sri Guru Granth Sahib, not a human being. And Vedantic beliefs and practices are older than Sikhism, yes. But Sikhism is not the child or offspring or a subdivision or a sect of Vedantic philosophy. There are major differences. So the distinction needs to be made clear. That is all I am saying.
Reference:: Sikh Philosophy Network http://www.sikhphilosophy.net/gurmat-vichaar/18394-naam-japna.html
But please don't take my comments as directed at you personally. They are nothing more than my understanding of where we need to be focused.