It's his starting average that matters, not his current average.
It says 'current Championship riders' so surely if Carr gets dropped then he's not currently a Championship rider and therefore isn't doubling-up so the quoted rule is irrelevant.
I thought riders over a 4.00 Championship average couldn't DU and ride NL as well. I think that's right, off the top of my head anyway. Or is it current average and not starting average?
You could've used Bickley etc until Hay's facility runs out and then used Roberts anyway as he would be an unattached 3.00. So use Roberts for a month but sign Halder with the intention of him riding once he's completed his exams in early/mid June.
What 4 teams are better then? I think there's a clear top 5 like Hunters has said.
It's still about winning as well as development. Try being a supporter of a stand alone team who's only speedway is in this division and you'll realise that you want your team to win, like in any sport.