Updated.
[member="Hakora Feanor"] - There's a 30-day waiting period for major factions counting from the day they receive major status. It usually happens alongside map updates.
[member="Karrie"] - The template for rank titles is available for download here:
http://starwarsrp.net/topic/17066-tefs-art-resources/
If you have Photoshop (you can download CS2 for free) simply pick a background for it and change the text to whatever you wish. As for you other question, yes you can be part of as many factions are you like, but only major factions will be available as official rank titles beneath your avatar.
Also, next time please PM me any questions you might have rather than post in here. No harm done, just letting you know.