At one time, the steering gear and tie rods were engineered for the life of the vehicle.
As were the kingpins back when those were used on cars.
If they were still engineered that way a Chrysler in 2004, I’d assume the suspension, engine mounts, and other ‘junk it when that goes wrong’ stuff to be ready for failure.
And the alternator, water pump, and timing belt (if any) will need replacing - if the seller can’t produce receipts itemizing those items, walk.
About the too much oil thing–within what time interval would any problems that were caused by this be expected to show up?
Like suppose the oil level was fixed, and no problems occurred for two weeks? Good? Six months? A year? Five years? How long would one need to wait before being relatively certain?
It’s interesting that you take the car to a mechanic, presumably to help you avoid make a bad purchase, and now you’re questioning the mechanic. While that may well be the right call after your interaction with him, it also looks like for some reason you really want to buy this particular car. Given that there is a list of at least potential issues, why not move on?
When it comes to tie rod ends there is no tolerance for wear, if they are not like new they need replacing. Not just because they may fail but a worn tie rod end also compromises your control over the vehicle.
That is the official textbook dictum, but in the real world the effect of a tie rod with slight play is negligible.
I agree with you on that, but from a mechanics point of view we have always been taught no tolerance. I have personaly never seen one completely fail.
Yep. As well as changing the coolant - it’s a nice thing to do but if it still has the appropriate color, there are no leaks, and tests OK - no worries.
I’d be worried about getting the full story on the rack & pinion unit, that’s easily a $500 part from a repair shop so $900 total may be low. In my world a 2004 Dodge Grand Caravan with 150,000 miles is worth $1500-$2000. Questions about the steering would kill the deal for me; plus you’re still talking $4-500 of fix-up parts if you do the work - food for thought.
With that sneering attitude you should find a new mechanic! :eek:
If you know the rack and pinion needs repair and the tie rods are not so good, I’d be suspect about the entire front end.
And I’ll ditto what everyone else had said about the transmission.
Trust me. You don’t want any advice from me on this. 
This does not speak well for the quality of the work that has been done on this car.
Either whomever performed the last oil change put too much in, or the owner added oil when he didn’t have to.
This is hardly a deal-breaker, but is like a seasoning to put on everything else.
I wish I could be more help, but a lot of what is listed here is something I’d have to see myself to develop an opinion on. And photos won’t do it either: I mean touch and wiggle and stuff in addition to just using my eyes. Are the tie-rod ends just showing predictable wear, or are they an indication that the power-steering repair was done on the cheap. Should they have been done as part of that power steering repair?
I am very hesitant to recommend that anyone buy a front-wheel-drive product from Chrysler with 150,000 miles on it. I know too many people who had something fatal happen to the engine or transmission in the 140,000-160,000 mile range in Chrysler FWD cars or mini-vans. But if that’s all he can find wrong with it, it sounds like a decent vehicle.
While it makes sense to verify the protection against freezing occasionally, that is a feature that doesn’t deteriorate and will only change if the antifreeze-to-water ratio is altered, such as from refilling with other than a 50/50 mix after having coolant loss.
A helpful test, not often done, is to measure the pH. When it gets to a certain degree more acidic than it was when new, that can lead to accelerated corrosion. Replenishing the anti-corrosion additives of antifreeze (which do deteriorate) is the reason for changing coolant as maintenance. The color of the coolant is not a reliable indicator of whether it’s due for service.
ETA: If it’s due for a coolant change per the maintenance schedule, the pH will almost certainly confirm that. It makes perfect sense to change it when called for.