Space in discussion is limited.

No, it isn't. Karma voting is good enough to be trusted with managing space concerns.

If you find that your posts get a negative karma score, then stop making those posts. Otherwise the community appreciates the posts and the amount of karma tells you for threads roughly how much.

On the other hand I have the feeling that weekly would be a bit too much to get optimal participation. There no reason to start with weekly. It's better to have a slower pace and keep up the project for longer.