There hasn't been any info/leak/story about what actually happens in that scenario. Presumably that will be discussed as part of the overall talks.  Can't imagine it would be straightforward as the 1 rider over 8.00 was to even out all the Championship teams. Whilst no one had been announced at Premiership level, I expect contracts have been agreed/signed subject to the league going ahead. Big crossover in riders though so would not be easy to solve! For example, allegedly Dan Thompson has been offered a large sponsorship deal to move from Ipswich to Leicester in the Premiership (before Chris Louis & Ipswich quit). Rumoured that he has also signed for Edinburgh in the Championship. Presumably then if its one big league he will want to ride for Leicester to get the sponsorship (which is based on him riding at Leicester). Edinburgh will possibly already have signed 6 other riders to fit just under 40 with Dan Thompson at number 1. If they lose him, then they would likely want to change other riders. Partly for that reason I hope it stays as 2 leagues. If Redcar are going to announce all 7,  then they must be reasonably confident of being able to track that 7 next year. Hopefully it's a good sign if they go ahead with the announcement. 

Hope you’re right but needs to run something to keep stadium open for speedway, 2 GPs is not enough, if there is no premier (looking likely)and they won’t go championship what is left ?  

Zero percent chance that happens. More chance of not running than just doing NL.

Fraser Bowes should do fine, looking back at his league scores for 25, generally he was his average, or r/r, or in double figures. Number 4 I presume?! He might even flourish at Wimborne Road, being a Pirate can do that to a rider. 

Nope.

The doubling up disease started in 2003 with the ill fated British League Cup.