From my understanding, the event is the storyline and ship. because the quests are dailies, I don't think the quests will disappear, and I think after the event you will be able to do the dailies and increase your reputation. Don't take my word for it though!

This is stating that your character is below the level cap for those missions. To fix this problem, level up your character, or get on a higher level one. Hope this helps!

Will there be an expansion pack for Swtor? If there will be, will it come with new advanced classes, or maybe even a new class?