I have Late Night, and it doesn't run slow for me. And my processor speed is a bit under the minimum requirements for Vista, too. Everything else either meets or exceeds the requirements.
I don't think I've ever heard of someone getting a "bad version" or a bad patch, but I suppose it's
possible. How likely it is, I can't even begin to say. But if you suspect this is the problem, you could try uninstalling and reinstalling it.
As far as sharing things you've created in the game: if you were planning on sharing them here, then you wouldn't need the launcher even if it did work. You simply click the "Share" button and it creates a Sims3pack in Exports folder (Documents/Electronic Arts/Sims 3/Exports). Then you create a thread in the appropriate place in the Swap Shop, and attach the file to the post. You'll find the guidelines for using the Swap Shop
here. As far as the official Exchange goes, I'm not totally sure there is a way to share without using the launcher, but there might be. Any other site will likely have their own instructions posted somewhere.
If you do intend on sharing things here, you should be aware that Carl's Guide has a strict no 3rd party custom content rule. Custom content and mods are one of the largest causes of game related problems (if not THE largest), and have been known to cause irreparable damage to game files and can corrupt game saves. Many people have wasted many hours of their lives reinstalling their games (sometimes over and over), and have lost countless hours of game play as a direct result of 3rd party custom content and/or mods. I'm one of those people, so I speak from first hand experience.
We have no issue with anyone who has a desire to create custom content. In fact, if you wish to do so, more power to you. You just can't share it or link to it here.
If you have any questions about this rule, or any other rule, there's a link to them in my signature. If you don't find the answers you're looking for there, feel free to send me or any other moderator a message, and we'll be happy to address your questions personally. The only dumb question is the one you don't ask.