They should indeed be somewhat parallel, in layman's terms... Having them be at differing angles causes bumpsteer more than anything... The vehicle will swerve left-right as you compress and release the suspension, or will swerve one direction or the other when you get on the brakes hard and cause the front to dive... Parallel within a degree or so is the "standard" for a well-behaved vehicle, but the links must also be fairly close in length ideally. Parallelism is checked by connecting the pivot points with a virtual line, not by checking the actual rods, which are seldom straight between the ends...
A big mistake that used to be common was running a dropped steering arm to level out the drag link while leaving the trackbar at a significant angle. Big angle difference produces very noticible bump steer... You cannot put a drop steering arm on it wihout also dropping the frame end of the trag link, but that's the wrong ends of both to move. Instead, the axle end of both should be raised so that the roll center is raised closer to the CG, not moved farther from it... A 2.5" lifted WJ should have no death wobble problems or bump steer due to the lift, particularly if you keep the stock wheels and have the tires dynamically balanced. (dynamic = weights on both sides of the wheel)
FYI, death wobble on Jeeps is typically caused by some combination of shot bushings in the control arms and track bar, loose balljoints, wheels with less backspacing than stock, and heavier tires that are not dynamically balanced (weights on the inside AND outside of the wheels). Poor caster can also contribute, as can increased lift height, loose steering boxes, etc. Some vehicles are more sensitive than others... WJ's are not in the high risk pool as far as I know...
