Re: Hindus - Sikhs
May be both. GuruGranthSahib mentions the writing of 36 persons including Gurus, out of 36, 16 are Kashmiri pandits, mainly Bhatts. AdiGranth’s essence is very much similar to basic hindu teaching, Hindus never had problem of embracing any religion to this day, Sufi mazaars like that of Ajmer and Delhi attracts very large number of Hindus, similarly on any general or festive occasion there will be as many Hindus in Gurudwaras as much as Sikhs. It is much easier for hindus to followe two relgions simelatneously than any other faith due to Hinduism’s basic nature of assimilation of thought .
And that is probably the reason behind inter-religion marriages. A little off topic, but were the marriages between Hindus and other religions common before Mughal Era?