I don't know if you've already stated this in a previous topic before, but I've gotta ask about Kurohime's events.

Will there be a way to recruit her, meet Citrinne, and marry Kurohime without waging war in the future? 

Also, would there still be the option for Brad to make a harem or be happy with his girlfriend without making a move on him as a girl?

No, preparing for war will be necessary for Kurohime's events, as it's part of her storyline. However, you're not declaring war, just preparing for it, which actually has no negative effects or force you to anything.

When you don't advance the female route events for Brad, his future in the time skip event can obviously be different but also happy.