There's no such thing as castes within Sikhism, this is completely AGAINST our religion. we believe in Equality. Within punjabi culture, there are some people who speak of caste. As for arranged vs love marriage: Marriages in india used to be very different than our idea of arranged marriage. There would be someone called a vichola who knew everyone in their village very well, and had known the families for a long time. Knowing the personal characteristics of a man/woman and their families he would try to arrange the match, and it was up to the couple to accept or not. It's completely a personal thing as to whether you think arranged versus love marriage is better for you etc. because people will have different opinions on this and will contradict each other based on their own observations and experiences. I'm not sure what you mean about fighting harder to remain faithful (stop being unfaithful), i mean if a marriage is based on two souls, and a deeper spiritual meaning, it shouldnt be hard to remain faithful in any situation love or arranged.
Please can someone give brief explanation of the difference between different castes within Sikhism and is there a way to tell what caste someone is part of?