I can use Sri Guru Granth Sahib Ji to promote anything I wish, by god its done here by Hindu orientated minded people to Castists and so on, that's why these texts exist, to show the real meanings and arths. So find it in practice where Sikhs followed it all. Find sources from the 17/18th centuries where Rehitnamas from Guru Sahib were used and prove your points. All I'm asking you to do is provide the historical proof, which you seem to shying away from.
If that's too much for you then don't ask others to provide evidence in ANY thread when you can't do it yourself.
Your "evidence" is 1 quote, the first line. That's all you know about SSGS, the mool mantar and nothing more, you can't even read Gurbani and you obviously don't. That very quote can be used for ANYTHING, to promote ANYTHING.
What source other than the sggsj do you need.. Why do you want something from the 18th and 19th.. When you can go back to the 15th and 16th..
how idiotic can one person be? Are you really suggesting sikhi doesn't promote egalitarianism?
There's no such thing as humans using 10% of their brain, that's an urban myth that's been disproved multiple times. That question in itself is slightly insulting to Guru Ji (not saying you did it on purpose OP, nor am I attacking you in this). Guru Sahib was infinitely powerful, they were as powerful as they needed to be.
Think of it like this, A village has a competition every year to lift weights, the competition is the only one and the villagers believe that no one can lift anything more than say 100kg. A stranger comes to the village and competes, winning the competition without much effort. From the villagers point of view that's his limit, as they can't fathom the concept of a person lifting anything more.
Just like the villagers we can't fathom the depth of the Power of Satguru Nanak. So its best if we stick to applying these sort of restrictions and levels/limits to humans and not the Sargun Saroop of Waheguru Ji.