If the format had to stay the same, then the problem to address is how to keep the teams and supporters interested, to do that you need to give all teams the chance of getting into the top 4. But the additional problem is making sure teams take it seriously once safe and there doesn't become a culture of providing we are in the 8 we know we can win it.
I believe the following would hit an acceptable compromise
[list Give the league leaders shield after 23 rounds - provides an incentive to finish top
Give the top 4 the additional home game - provides an incentive to finish higher up the table
Each team starts the super 8s on half of the league points accumulated in the first 23 rounds (rounding up for half points) - brings all of the teams closer to each other, this year there would have been 7 points between 1st and 8th and 4 points between 4th and 8th - achievable targets[/list

I don't think that anything would be completely acceptable to all in the 8's format but this seems to address the major problems.

They could if they increased the salary cap and worked on quality rather than quantity.

But the clubs couldn't afford it. Wigan have lost around £600K and Saints about £1.6 million over the last two years, so where's the extra money to play players going to come from?

Speculate to accumulate?

Better quality = better crowds = more sponsorships = more money?