So they went ahead and actually welded it??? I guess it's too late to go back now.
Is your steering pulling, or did they just not adjust the drag link so the wheel is straight? If the drag link isn't adjusted right, it can feel loose, and can cause the LCA rub (in one direction) if your steering stops are not adjusted right. Easy fix though, just do it yourself.
Your vibes are probably coming from bad DS angles. Did you do anything to re-adjust them after the SYE install? Your pinion should only be pointing about 2* lower than the DS.