I am so sorry that you are having to deal with this.
It sounds like you have made up your mind to speak up against the Watchtower. The past can not be undone. Even if you take down the Youtube videos, they could still shun you? Are you willing to rejoin the Kingdom Hall, pioneer, and be a 'good girl'? It may take that to get back into their graces. You see, your parents follow a cult. They will only accept you completely if you are a part of the cult. They speak in group speak, and do not see individuals. People can not have an opinion that differs from the Organization. Therefore, I would use the Organization's words against them. Fight fire with fire.
How about letting things cool down for a little bit? Then, send your parents the July 2010 Awake article on shunning. http://www.jehovahs-witness.net/jw/friends/175088/1/rough-draft-re-shunning-new-Awake-article
There is probably other threads/copies out there on this important Awake that is on YOUR side. This Awake says, basically, that everyone has the right to belong to a religion and to leave a religion, without losing their community. In other words, it appears to be against shunning. Of course, the example in the Awake is someone coming "to" Jehovah and shunning by their former group. But, it may get yoru parents to think.
My JW relatives seem to be trained that 'there are two sides of every story' and 'everyone is entitled to thier own opinion.' I use this to my advantage.
I would stick with telling your parents that you've done alot of study on the Watchtower and find problems with many things. Ask open questions, "Dad, what would you do if you found out that there is a masonic pyramid on your religion's founder's grave?" "Dad, what would you do if you found out that the Watchtower corporation is worth billions, and they never release this information at the local Kingdom Hall?" "Mom, what would you do if you found out your religion took an active role at hiding and promoting pedophiles?" "Dad, what would you do if you discovered that Bethel misquotes" "Mom, what would you do ...." You may never convince them to leave, but they will have to respect you as having an opinion, and an opinion that is well researched.
As always, I tell my relatives this, "I have researched the Watchtower, and on many fronts I have found problems. It's not for me." They know that there are problems, but are still at the point of sweeping them under the rug. On some level, they identify with me.
I do tell my relatives if I am doing something against the Watchtower, but I wait until just after I did it. I tell them that I'd rather they hear it from me then from the Internet or Friends that, "Just to let you know, I ... I'd rather you hear it from me then from the Internet or relatives..but last week I met with a journalist........" I usually do this through an e-mail. I never get a reply back, so I don't have to deal with the, "Skeeter, how could you disgrace....!" bull.
While I was never baptised, my JW relatives do not shun me. We don't talk often (about once every few months), but there is an open line. In fact, they have told the congregation that, "Skeeter has different opinions. I don't agree with them, but everyone has the right to thier opinion." One relative even called Bethel to tell them that! Bethel passed this person around to a bunch of different people. I don't know who all, but I do know it was a bunch of different people. I think the relative called Bethel to make sure it was on record that he didn't agree with me, and he was very nervous about how what I did could affect his standing in the congregation. Remember, JWs are very afraid of what other JWs think. So, they do strange things like shunning or calling Bethel to report on you. Allegiance to the Watchtower is greater then allegiance to family.
I also told one JW relative that I knew that she valued me as a person and I thought highly of her as she thought of family first. I commented that she didn't shun me for having a separate opinion. I told her that shunning opposers was one characteristic of a brainwashed cult follower. I didn't get a reply e-mail. So now, if she shuns me . . . she's proven to me that she's a brainwashed cult follower. She's damned if she does, and damned if she doesn't! :-).
Skeeter