$500 seems fine. What you describe are easy fixes. The 1st gear bucking could be from broken engine or tranny mounts. Headliner is easy to renew for about $130 tops and a few hours of work. Rear non sport bumper should be easier to source plus drivers mirror cover. power steering pump or a worst the rack are easy to replace if you have a place to do it.
Could be a good car for someone who wants to put in a little renew time and a $500 for new/used parts.