Well Dave its like this:
The closing assist pump is probably defective, I saw a post recently that said the locks need lubrication and the pump sees the inability to close as a fault and goes into failuremode. I am not convinced but $600 or so will get you a new pump. The clunk you hear in the back could be a bad suspension strut (looks like a shock with a hose going to it) If the back end is bouncey you probably have bad hydraulic accumulators $300 to change both, $450 for each shock.
The car phone is history, it is probably the factory OKI that is analog, and no one will activate them. I would not spend time on it. There might be a carrier or two in the US who might consider it, mostl in riural areas, with an antiquated system.
The seat ajuster I have no experience with, but if the control is out someone played with it. Who cares if the rear seat does not work, only the backrest moves unless you have four seat option.