For me for speedway to survive and thrive into the future is to have credible 2 main leagues of equal amount of teams.
promotion and relegation between the leagues. One up and one down.
play offs in division 2 for promotion and playoffs in division one for relegation.
whoever tops the table is league champions.
im the top league every meeting should be meaningful wether you are fighting relegation or trying to be champions.
in the second division the battle is for champions and the playoffs would decide promotion
if you could get a tv deal and decent sponsorship for the leagues the money should be divided up into prize money depending where you finish in the league.
a extra payment would be given to the promoted team to assist them in transition to the top league.
a credible league could attract good sponsors and a promotion and relegation battle would make excellent tv.