The current era is one of a wealth of incoming high precision cosmological data from cosmic microwave background (CMB) and large scale structure (LSS) surveys. Yielding precise measurements of the kinematic Sunyaev-Zel'dovich (kSZ) effect, by cross-correlations between the two, has the potential to take advantage of this unique time. In the first chapter of this thesis, we conduct a study on how to achieve this, focusing primarily on systematic effects such as miscentering. Photometric and spectroscopic galaxy tracers from SDSS, WISE, and DECaLs are considered in combination with CMB data from Planck and WMAP. With two complementary techniques, analytic offset modeling and direct comparisons of redMaPPer brightest and central catalog samples, we find that miscentering uncertainties average to $0.4-0.7\sigma$ for the Planck kSZ statistical error budget obtained with a jackknife (JK) estimator. Our results demonstrate that uncertainties introduced through using galaxy proxies for cluster locations will need to be fully incorporated, and actively mitigated, for the kSZ to reach its full potential as a cosmological constraining tool for dark energy and neutrino physics. A 5.1$\sigma$ detection of the pairwise kSZ signal results is obtained with four seasons of ACTPol data in combination with Planck CMB with the luminous red galaxy sample from the Sloan Digital Sky Survey Baryonic Acoustic Oscillation Survey (SDSS BOSS) DR15 catalog, in Chapter 2. We utilize the constraining power of the kSZ effect by fitting each of nine luminosity selected samples to theoretical pairwise predictions, to find kSZ-derived mass-averaged optical depths, $\tau$, and their evolution as a function of cluster mass assuming a Planck cosmology.