We are often asked what maximum crystal resistance should be specified. The best answer to this question is the lower the better, but use what's available. The crystal resistance will have some effect on start-up time and steady-state amplitude, but not so much that it can't be compensated for by appropriate selection of the capacitances CX1 and CX2.
Similar questions are asked about specifications of load capacitance and shunt capacitance. The best advice we can give is to understand what these parameters mean and how they affect the operation of the circuit (that being the purpose of this Application Note), and then decide for yourself if such specifications are meaningful in your application or not. Normally, they're not, unless your frequency tolerances are tighter than about 0.1%.