- the heroine had family interpersonal issues
- the heroine had a family member who was also a criminal
- the heroine, in a prior job she had apparently was responsible for a death of her colleague (yes this was a romantic suspense trope)
- the hero knew of this heroine in the past and felt responsible that he should have handled that case
- the hero has interpersonal issues and cannot get along with anyone
The point is, this is simply too much.
Not only does adding all of this extra stuff to the story make it difficult to tie it all together, it bogs the story down. Readers have to now juggle all of these issues. What, unfortunately, gets left behind, is the central story arc.
I know that a lot of people add all of this extra stuff (I keep wanting to say another word but I want to keep this clean) because they were told that their characters "had to have a reason for doing this." Do you want to know something? You don't!
People CAN be who they are simply because of their personality. I am pretty much a business type of person and tend to keep things pretty serious simply because I have always been that way. No, I was not abused by parents. No, I did not have a traumatic experience in a prior job. I just tend to be focused that way.
If you want to tighten your story up, the best thing you can do is get rid of that baggage. You may be surprised that readers will be able to connect with your characters better.