With the 26 pulley you donīt drive any split on the tires. Just used when you drive rubber tires, like in rain.
I like to drive always softer tires in the front than in the rear. First you have more steering and you tire wear is much better.
In qualifying you can use for example 35 front and 37 rear and for the finals 37 front and 40 rear. On high grip conditions or when itīs very warm, you can go higher with the shore.
The 600cst oil is too thick. But I think that is just the starting oil. So that the car is easy to drive. Donīt forget, not everybody who buys a MTX-5 has experience with that class.
I would start with the standard pistons and use 400 or 450 oil and also use the standard springs.
I would also change the ackerman position and would push it to the most forward position.
The next thing is to check your track width. I prefer to drive the front a little bit less than the rear. For example 197 or 198 in the front and 199 in the rear.
What a lot of people forget to check, is the downstop. In most cases you can use 4 in the rear and 1 in the front. But sometimes itīs important to play with it. The effect in my opinion is great when you change for example to 5 in the rear and 0 in the front, or only 0 in the front and 4 and the rear.