1) There is a difference between legal immunity and the ability to raise funds -- for which she was banned according to the letter.

2) Her reason for banning, according to the company's letter was fundraising. That is certainly a type of speech.

3) Ships in the water circling to pick up people certainly makes them take riskier actions, or pushes the risk threshold low enough that people are willing to try.

I personally think that an open border solution would be much better for everyone. I also think that international law is valuable, and painting this situation in which these people are actually being transported by trafficking rings for at least some portion of their trip is not as black and white as you portray it. I'm personally against a modern day work and sex slave pipeline from Africa to Europe, and there is a non-negligible chance that that's what is happening here.