About Deleting Old Topics:
I see your point, and I'm guessing you mean old topics that are similar to something recently put up. There are places that say to put up a new thread instead of bringing up old stuff. And there are places that tell you to use a search and look up someone who's already said what you're about to say. Neither is right nor wrong. So what's a guy to do? Well, you're a man. If someone has said words in the past that's worth keeping. Keep it. If you think you can word it better, than word it better.
A perfect example: Those 1-2 year old SFIII 3S Beginner Threads...
About New Members:
An internet forum is a site with topics, posted replies, and shared ideas. You start taking those things away and you don't have a forum anymore. I don't see why a New Member should be held back anymore than I should. They've got ideas just as much as the next person. Let them put it out there. You will still get members who do things like spam, and be stupid. But that's normal. It's the internet, you've got all sorts of people here. The idiots will be dealt with case by case.