I understand peoples desire to see locales and other things from the movies, but I don't think fantasy flight should put them in unless it is a really good reason.
Leia would make a good ally, much like Luke, Han, and Chewie but many seem to want the mivir heroes to be playable in this game. I don't think that is appropriate. This game is not about those heroes' story, we see that on screen, but about the new characters FFG have created.
The desire for Jabba is understandable, again because he was in the movie, but you have to think: what would he do? In the movie he sat there, talked/yelled and died. I would rather see a new hutt character created. Perhaps a younger hutt with less influence that is not as corpulent and trying to rise in rank of his kajidic. This would make a more interesting opponent than Jabba, and fit into the game better than trying to shoe horn in Jabba. The mission that has the hutt if won by the rebels let's them deploy mecenary forces in a campaign. If the empire player wind, they do so for cheaper.
Iconic characters from the movies should be kept as allies at most. We should get some new heroes created. I'd love to see a Mon Calamari Character, as well as some more female heroes. Jyn and Diala are fine, but I want a badass female soldier like this: