The weeklies minimum will probably vary from series to series. The current series is set at level 6 because that's the level when you get sent to Eta Eridani - the zone it's in. The Breen were set at 10 because they wanted the Breen to have some abilities not generally available below 10. I'd imagine if they ever do a weekly set in Gamma Orionis that it will be RA3. I'd also expect to see a weekly eventually set in Pi Canis (since they're opening up that sector for Klinks) and it will probably be around level 18.