You can cope with fictitious people simply by using the add unrelated individual.
They will show in the index but not be associated with the family lines unless you decide to attach them
As for new features
This is the linkhttp://community.ancestry.com/feedback.aspx
Make sure that in suggesting an idea that you explain why it would be useful and how you would use it. Make a strong business case. You are competing with a myriad of other enhancement requests and I guess only so many will get into any future version.