So I have yet to get Showtime, mostly waiting for the price to drop. But my question before I get it, if I get it. Do the careers require you to simport in order to be promoted? I tired Googleing but I didn't get a straight answer. Thanks ^_^

Simport is just sending your performers on tour. But you don't control them. They're hosted on someone else's game.

No. I never simported once and had no problem progressing through the careers. I did need a mod, available on this site, which unlocked all the stage stuff that required Simporting to unlock. Yet it is still possible to progress even without those stage props if a mod to cheat around that bothers you. Personally, I'd just go with the mod.

With Showtime, you can progress in your performer careers just by delivering Sing-a-Grams (singer) and/or performing on the street for tips. Performing on stage is much more enjoyable to watch though in some ways. Simport is not required.

By using Simport, you can unlock some stage props and outfits. Velocitygrass has unlocked these objects so you can have them in your game without having to send your Sims all over the Simuniverse. These are official EA objects.

http://www.modthesims.info/download.php?t=470934

I think all it would do is give you new shinies and make your Sim advance that much more quickly. I never use it...when I play a game, I don't feel the need to invite the whole world to share in it.

I have the YA age set for 30 days and adult for 23. I had a Sim get to level 10 in the singer career before she hit middle age, even with time out to have a baby (her husband was of help there, since I gave him a first-shift job and the professions tend to have evening hours).