If you don't get five stars, you won't get as many fans or you'll lose fans depending on how you did. So, it's always good to get five stars because you'll gain lots of fans, and gaining fans is a significant part of the game. It is how you move from E list to D list to C list to B list and finally to the A list! :D
To add a friend to a project, you click the button that has silhouette of a person, shoulders and up. There is also a little plus sign on it. Once you click that you can add anyone on the list to your project by pressing the "call" button. Hope this helped! :)
Click LAX California! From there, you will see a button to the far left of the room, click that. Now you can use the bus again, which will be on the left as well, to get back to Hollywood, Beverly Hills, etc... :D
I was confused at this part too! So, all you have to do is just complete the tasks you have before it. One of those tasks is needed to be completed before you can speak to the media. I forgot exactly which one it was though, so just to be sure you should finish both tasks. :)
I may be wrong for others (I would wonder why), but I know for sure when I play the game that you do not have to wear any star or heart items to photoshoots, dates, etc... but only have then in your inventory. So you do need to buy them and accumulate the number of stars and hearts but you can wear whatever you want.