1. A method for characterizing an accessibility of potential stimulus sites in connection with surgical planning for implant of a cardiac medical lead near a heart of a patient, the method comprising: obtaining image data representative of a coronary venous system for the heart of the patient to receive the lead; generating a venous map, based on the image data, representative of venous pathways for the heart of the patient; analyzing the venous map to identify pathway features of interest (PFOI) within at least one select region of the venous pathways; assigning scores to the PFOI based on at least one of predetermined feature-complexity relations or physician-entered complexity updates; and displaying treatment planning information to a user based on the scores.