Hmm, why didn't I get a email with the other posts??? Sorry that I didn't answer...
@MyXxed:
1. I'm not sure what you mean. If you set them to a standard forum all threads will be kept, but no newsgroup function will be anabled any more...
2. Well... if you call the script via command line for example, there will be no time limit. If you call it via web, It is called by apache and the time limits of apache may kill the script. I don't think there is something you can do except you are the owner of the server...