We carry out a quantum-mechanical analysis of the behavior of nodal quasiparticles in the vortex-line liquid phase of planar d-wave superconductors. Applying path-integral technique, we calculate a number of experimentally relevant observables, and demonstrate that in the low-field regime the quasiparticle scattering rates deduced from photoemission and thermal transport data can be markedly different from that extracted from tunneling, specific heat, superfluid stiffness, or spin-lattice relaxation time.