Question for victor-200

Hey I got a couple questions for you. I dont know if theyve been addressed but beyond the first page I didnt have to scroll through them. Hopefully they make sense as with Lost sometimes the questions seem to become more confusing that the answers! Anyway here they are and thanks in advance!!

I was wondering at the end of season 2 you see those guys call Penny after some kind of quake or something. Then you assume her boat is there but we find out its not and its her Dads. After they actually leave the island they come to Pennys boat. Now my question is why is she out there looking for the island? At this point she didnt know where Desmond was right? The whole thing just confused me.

Also why did they have to lie about the island when they left? Witmore knew the island could travel and that most likely people were alive on it. So them lying about being on the island didnt actually stop Witmore from continuing to try to go back as he had searched for years to come back to begin with. So exactly what was their point in hiding it? Jack says its to protect the people they left behind but the only person that would be a danger to them would already be out looking for the island again anyway right?

Shut up talking spaceship! I'm trying to watch my favorite sci-fi show.