If you insist on putting on the mantle of public defender of Planned Parenthood then perhaps you will take a little advice about two silly things not to say while framing your arguments.
1. Charge that the videos are edited/selectively edited/highly edited - First of all, selectively edited is just repetitious. The very process of editing is selecting the key points and removing material deemed less relevant.
Every news article, whether print or video, is edited. Editing is necessary for concision, which is necessary to reach larger audiences. The Center for Medical Progress released the unedited versions simultaneously with the edited versions so that anyone who wished to watch them in their entirety could do so. They are not hiding anything. They simply realize that if they released a two and a half-hour long raw video investigative piece it would never be seen.
We consume edited news all of the time. It is necessary. It also means that the point of view of the news source is always a factor to be considered. ALWAYS. Our job is to examine the evidence and make certain that the point of view of the source hasn't corrupted the evaluation of evidence, not to complain about editing as if that fact alone established anything.
2 - Refer to abortion as settled law. Abortion is inarguably legal in the United States. In fact, our abortion laws are more permissive than almost every other nation on the planet, but that is another discussion for another day. You may be happy about that fact, or it may distress you.
Its legality is in no way a defense of its moral legitimacy. This is obviously and demonstrably true. It was once settled law, affirmed by the US Supreme Court, that black people could be properly owned as property (Dred Scott v Sandford 1857), that certain citizens could be sterilized against their will because "three generations of imbeciles are enough" (Buck v Bell 1927), that the separation of the races was legal (Plessy v Ferguson 1896), and that the forced internment of individuals based solely on Japanese heritage was a public good in time of war (Korematsu v U.S. 1944). Eichmann argued during his Jerusalem trials that his prosecution was unjust because he broke no German laws in his participation in the Holocaust. He acted in accordance with the orders of his leaders and the laws of his nation. You would be hard pressed to find one of the pundits that blows the settled law trumpet today willing to approve any of those formerly settled laws.
Settled law is frequently unjust. That is precisely why we have a history of great cultural reformers. William Wilberforce, Frederick Douglass, Susan B. Anthony, Lewis Hine, and Martin Luther King Jr. are admired because they operated on the principle that unjust laws ought to be changed. They battled against immoral settled laws and earned the admiration of generations beyond them for doing so.
Our system of government is designed to allow us to revisit laws all of the time. It is true that we place certain legal principles higher than others in importance, it is much harder to amend the Constitution than it is to change a local ordinance, but no law is beyond our ability to change should the will of the people of the United States be sufficiently rallied. It is silly to pretend that we are done with the issue of abortion and are no longer allowed to publicly address it, but it is much easier to shut down discussion with declarations of "Settled Law!" than it is to reasonably defend the morality of it.
I understand that there are people who ideologically line up with Planned Parenthood's view of abortion as a good. That agreement does not obligate anyone to champion Planned Parenthood against the current charges, but if you must do so, please don't do it this way.