I'm pretty sure Narrative won't tolerate bots. It doesn't seem like a community that would put up with it for long.

And, probably, upvoting a post which other users downvoted will lead to a reputation loss, but I'm not sure.

I hope not. I can't imagine why it would be a reputation limiter to be a minority. That would be awful!

Also, where do you get the information that the niche suggester receives 10% of the niche sale? I could not find it anywhere.

Right here

Once the niche is paid for, the person that suggested the niche receives a commission equal to 10% of the fee paid.