"Borderline" indicates that the trait is only very slight. The person who has them probably wouldn't be aware of them. It usually refers to traits that are negative or would be a problem if they became more intense. ADD means you can't focus your attention where it needs to be. Borderline ADD means OCCASIONALLY you can't focus your attention where it needs to be.
Borderline personality disorder is something that has to be diagnosed by a PROFESSIONAL. For an amateur to try to make a diagnosis from a website checklist would result in everyone being diagnosed with borderline personality disorder. If you think you have a problem, see a doctor. If you feel someone else does, encourage them to seek help. http://www.nimh.nih.gov/health/topics/borderline-personality-disorder/index.shtml