The solid surface density profile of protoplanetary discs, and the composition of these solids, can be formed through sequential condensation models of dust precipitating from the cooling gas of the solar nebula. I continue developing a code that reproduces the chemical compositions of most chondrites as well as the bulk compositions of the rocky planets using our partial condensation model with an evolving disc. I extend this validated code to exoplanet systems with different initial elemental ratios, like the carbon-to-oxygen ratio and estimated stellar abundances over the age of the universe. I have improved this dust condensation code to include isotopic fractionation of elements as certain isotopes preferentially condense over others. Isotopes provide additional constraints to improve our model’s reproduction of the rocky solar system bodies and, thus, enable more informed models for extrasolar systems. Additionally, I continue my dynamical work on the sporadic rotation of tidally locked planets that arises from the interaction between tidal locking and orbital perturbations due to mean motion resonance. Previously, I examined sporadic rotation in the system TRAPPIST-1. I find a new exoplanet system that likely exhibits sporadic rotation around a high-mass M-dwarf star, K2-3. Additionally, I find no sporadic rotation in the other systems I examine and validate my model against the Jovian moon system. I show the impact of these complex spin states on planet climates in high-mass M-dwarf star systems and compare them to low-mass M-dwarf models.