In this paper, we study the problem of embedding the high-dimensional spatio-spectral information of hyperspectral (HS) images efficiently and effectively, oriented by feature diversity. To be specific, based on the theoretical formulation that feature diversity is correlated with the rank of the unfolded kernel matrix, we rectify 3D convolution by modifying its topology to boost the rank upper-bound, yielding a rank-enhanced spatial-spectral symmetrical convolution set (ReS-ConvSet), which is able to not only learn diverse and powerful feature representations but also save network parameters. In addition, we also propose a novel diversity-aware regularization (DA-Reg) term, which acts directly on the feature maps to maximize the independence among elements. To demonstrate the superiority of the proposed ReS-ConvSet and DA-Reg, we apply them to various HS image processing and analysis tasks, including denoising, spatial super-resolution, and classification. Extensive experiments demonstrate that the proposed approaches outperform state-of-the-art methods to a significant extent both quantitatively and qualitatively.