These are just suggestion for tpt, I do not know much if it is computationally feasible.

first, the ability of gases to expand and compress, as deut, and pressure would be given by temperature and density, which is affected only by contact with the gas, and not as it is now, since there is no gas. All gases tend to expand, to life 1, the more temp, the faster it expands, where only elements, liquids and gases can drive pressure, i like rockets !!!  data: pressure = c * density_of_gas * sqrt (temp) * life, c = constant

Gravity, I see that it can function as it is scattered pressure, and that each element, gases, liquid, together with its density, spreads the force vector itself. And should also have room properties, a scale factor, that affects thermal conductivity, speed, scattering, pressure and then gravity and others.

In radioactivity, neut, and prot should not change the pressure, and its penetrability should be the opposite, because the prot has charge. In the fusion, I see problem in the release energy after the reaction, and it is not self-sustaining, for example in a star, the fusion should be probabilistic according to density and temperature, and releases much more energy than was used to generate the reaction. the plutonium and uranium should have a tmp, concentration of fissile material (How about making a machine to make uranium enriched?), along with scale factor determines the critical mass, the ability to fission when the neutron passes over it and not by the pressure it affects, but rather the density too (with too much c4 around, do you think it would not compress it?)

In the oxygen, incendiary materials only burn in the presence of oxygen.

There is no limit to the temperature, 2147483648 is better (mainly for fusion and fission)? the aheat can only add the temperature, use a rate of change, which decreases the source and increases the receiver and the same happens vice versa, it is worth remembering the radiation of the blackbody and verify how much the emission increases.