Trac bars won't overstress those parts. If anything it may allow the spring bushings to better distribute the stresses. As long as the frame is good, the spring hangers are solid, the springs are new and the bushings are new it won't do anything bad. Ball joints, rod ends and wheel bearings are more stressed by offset wheels, large tires and hard cornering. The trac bars keep the axle centered, true, but without them the only stress points are the the shackles, shackle mounts and bushings. Keep the swaybar....
89' YJ Larado 4.0L,AX15
05' Grand Cherokee Limited, 2"OME lift and a Hemi.