2004 Cavalier.
So.. I'm driving home from work the day before New Years eve and my car breaks down in the middle of nowhere. No shops have openings until Tuesday and car must be towed a long distance. I write this story because when stuff breaks down, it always breaks at the worst time which is why I decided to ask about general maintenance. It was the fuel pump that went out which I planned on replacing when I was finished with my garage. But the garage still not finished .

Since it is much cheaper to replace items yourself before a tow is required and you can do it at your leisure, not when you have a bunch of deadlines to meet. I would really like to get another 90k out of the car.
We all know to do things like:
Oil/filter, Air Filter, Spark Plugs, Belt, Coolent

So my question, what items should be replaced that are known to fail after 150k miles?
Fuel Pump!
Anyone replace the alternator after so many miles?
Rubber Hoses?
When to do an engine overhaul?

My manual says to never replace manual transmission fluid. What is everyone's experience with that?

Honestly on some components it soley can be time,age or condtions the car is exposed to.Just the general idea is do tune ups as required by mileage.I generally replace my belts(or just a belt if a serpentine) and def coolant hoses every 4 years as this is recommended by manufacture's of hoses and belts.I do this on all my rides.As for say the alternator or starter just keep your terminals (positive and grounds) clean from corrosion.As for the battery same along with removing the water caps to ensure that is level (if a sealed top battery) nothing to do.As for checking say the brakes,struts and ALL suspension like cv joints (boots) ball joints,A arm bushings,stabilizer links,tierods just verify each tire rotation 5k for any odd wear,leaks or noise.There are going to be items that just fail and even a good maintenance program will not prevent some failures.I could write more but,this is a simple short list and just paying attention to these generally you will catch issue's before a real problem kicks up.I check struts for what I call the 1 push down on the front fenders,and rear quarters for a single bounce for a properly working strut or shock.However a strut or shock can be wiped out and never show more than 1 bounce back up and be blown out.Also keep in mind how the car handles shows suspension ride comfort hard to normal (common sense) there.I think this is simple and unless you want more idea's how old are your wiper blade's.Just ask if really need something specific or otherwise.

There are several (fairly easily replaceable) things that are going to fail but (as the owner of two 1996 2.4L Cavalier convertibles that I bought new) I can tell you that the parts lifespan is VERY variable so I don't think it's worth preemptively replacing them unless maybe you take a lot of long trips.

You didn't say which engine you have but on the 2.4L:

* The water pumps are failure prone. One of my Cavs blew at 38k & 117k. The other at 62k. On the 2.4L it's a ridiculously labor-intensive job (like 7 hours) to replace a cheap part. (Replace the thermostat, seals, and timing chain tensioner when you're in there.) Sometimes they leak slowly and give you some time to get it fixed. Sometimes they gush badly and would be difficult to drive any distance without overheating.
* The timing chain and tensioner needs to be replaced at about 200k. (Consider replacing the water pump & thermostat while you're in there.)
* The starter on one of my Cavs failed at 85k. The other Cav starter is fine at 123k. Probably not worth preemptively replacing since they tend to give some failure signs, and you seem to have a manual transmission that could be push-started until you get it home.

On the chassis:

* The bearings can go at any time... but they usually start making noise so you have time to replace them.