Vibration and slight left to right pulsating steering wheel at speeds above 60mph?

June 2011 I bought a used 2005 Hyundai Elantra GLS: with 72,000 miles, previous owner is a female college grad. Vibration and steering wheel shake at Highway speeds: Since I felt it more in steering wheel than in seat I assumed front is where the problem lies. I also noticed shake and uneven braking when braking from Highway speeds so for ($90) I replaced the right front warped rotor, re-surfaced the driver side rotor resulting in fixing the shake at hard braking from highway speeds, however steering wheel and car vibration still present at speeds over 40mph. I checked front suspension for problems: ball joints, inner and outer tie rods, hub bearings, Struts, strut mounts etc. Found right front hub rotating with a little run out – so figured hub was bent = replaced hub and bearing ($121.60). When removing steering knuckle the ABS sensor would not come out so I had to drill it out and then clean out the hole’s corrosion so a new ABS sensor could fit, New ABS sensor ($58). Mounted and dynamic balanced 4 new tires ($357.00) due to previous owner never rotated tires and the fronts were worn past recommended tread life. During rotation I noticed 1 rim with a wobble while spinning on balancer so I replaced this rim ($75) with a new one. Now after all this it improved by 40% but still had vibration and shake so I jacked up car and thoroughly inspected front and found a bad outer CV joint on driver side = I replaced both half shafts with remanufactured ones for ($129.27). Found a bad front Control arm bushing on Driver side so I thought why just change 1 bushing – replace both bushings and ball joint while I have it apart but found that parts to rebuild control arm only $10 less than a quality aftermarket control arm so I replaced both L/R front control arms ($186). I now took it in for a front and rear end alignment, afterwards no improvement in vibration. At this point I am extremely frustrated and angry after numerous do it yourself labor hours and parts costs and still not much progress. I now talk to a Just Answer Hyundai mechanic online and he recommends having all 4 tires road force balanced at a shop with a Hunter 9700 road force balance machine. I took car to Firestone in Manhattan KS for a road force balance for cost of $83. The technician said all 4 tires are almost perfect. Now I give up and take car to Hyundai dealer, their mechanic said he found 2 wheels with 4lbs of road force and 2 wheels with only 1 lbs of road force, and moved the 2 good ones to the front and bad ones to the rear and this improved vibration and shake by a bit more but still felt at 63 MPH and higher. He also said the 2 tires with 4lbs of imbalance rims where bent. Hyundai Dealership service bill $205.38. So I spent another $150 for 2 more steel rims. I mounted the rear tires on the new steel rims and still feel slight vibration in seat and steering wheel pulsating left to right at speeds above 60mph worst at 70mph and higher. It is much better than when I started but still not the ride it should have. In Parts, Shop labor at $ 1372.25 and over 14 hours of my own labor still not fixed. What else could it be?