I confident we'll win the league, whether it's tomorrow at Fax, or later.

If we win the Grand Final, we'll score 2.9786.

To maintain that score (replace the GF win and League win), we'll have to finish 9th in SL the following year (or 11th and win the CC).

Cas are "today" scoring 2.9714.

I still don't agree that winning the league leaders shield will get the bonus point.
It negates the value of the grand final.

I totally disagree the League leaders shield is a reward for the best team over 26 rounds and should be the Championship Trophy, The playoffs are a gimmick where a team can come into form for a couple of games

I'm not disagreeing with that. But the RFL don't agree and put all the emphasis on the Grand Final so I think it's unlikely to make the reward smaller.

No good disagreeing with me - you can read it for yourself in the handbook.

The reward for winning the GF is the points score for finishing 13th.

I have. And I don't agree with your conclusions.
We'll find out soon enough.

Hmmm...yes....

The League Standing points are a 3-year score, so our end score will be above that of 13th (or an average of 10th, 12th and 13th).

So yes, the "Championship winners" score really can only be for winning the GF...

The 3 year average + the bonus for winning the GF.

Apparently they have reduced the score for team top of championship and widened the gap between 12th in SL and 1st in championship

They have lowered the score for 13th place...but I think the actual points differences awarded between placings has remained the same.

I haven't seen a change. Where are you looking.

The original way of working it is

1. The final placings are worked out after playoffs, so even if you finish 5th, if you get to the final your position is 14th (if you lose)

You are then allocated the points for that year's position 14th. Each place is 1.11 less than the next.
That score is then added to the previous 2 years to get a 3 year average.

Once you have that, the scores are reordered to get a list from top of SL with 1.11 less for each position.

They then add the bonus score separately for GF and 1895.

It sounds complicated but it's easy enough to work out. The difficult being you need to work out everyone's scores to work out your final number.