  In this paper we consider magnetic Schr\"odinger operators in R^n, n \ge 3.
Under almost optimal conditions on the potentials in terms of decay and
regularity we prove smoothing and Strichartz estimates, as well as a limiting
absorption principle. For large gradient perturbations the latter is not a
corollary of the free case as the differentiated free resolvent does not have
small operator norm on any weighted L^2 spaces.
  We instead show that the spectral radius of such operators decreases to zero,
hence their perturbation of the identity is still invertible. The key estimates
are based on an angular decomposition of the free resolvent, or rather a bound
that holds uniformly for all possible angular decompositions. The proof avoids
the Fourier transform and instead uses H\"ormander's variable coefficient
Plancherel theorem for oscillatory integrals.
