Is it possible to have borderline when sme is still able to think about how to hide selfaflicted injuries and tortures best ?

Yes: Borderline in my opinion may be the worst of illness one can have because by virtue of the disorder they rarely if ever seek help. In an ironic way they get relief with there behaviors and those closest to them suffer the pain reguardless of what they do you seek therapy yourself the damage that a borderline does to those around then is often profound psychologically.