You can't really 'control' more than 8 sims at once but you could maybe take your household to a community lot where there will be more sims that you can interact with; or throw a party and invite over sims that you want in your movie.
Once your two married sims become elders, go to the phone and select the "Throw Party" option. One of the options should be "Anniversary Party".
you can have 3 because its sims 3!
yes, you can use the sims 3 code more than once.
Yes you can
if you are talking about the cheat gnome then yes you can use it more than once
You have to wait for the job to come around. After a few days it should have come around at least once.
You need to wait until the party starts, and once the guests have arrived at your party, click on one of them and go down and you see where it says 'Ask everyone to leave'.. Click on it, and the party will be over. Hope I helped.
Your sims on the lot that the sim has left can't visit that sim. You have to go to the house where that sim who moved out lives and have the other sims from the other house come over from phone invite.
The Sims 3 Store online is updated once a month, sometimes more frequently, with new content.
yes you can register it on more than one computer.
I'm afraid you can't have more than eight sims in one household together at a time. I had this family once, when I had sims 2, and I had eight family members and I couldn't get pregnant or adopt any other babies.