Ruined, thanks for the detailed reply. So you went through it, that is good.
While I have not driven SA and I have no doubt at all you drove some rough roads for long distances. I still feel it can be done without major or even a bunch of minor repairs.
As you know CA the roads are not all that bad. But you still have a lot of rough pavement. Potholes galore! I basically did the same thing to my 04 Taco before heading south. Brakes, not only changed pads I upgraded to Tundra brakes. Wheel bearings and seals, new ones put in. Rack & pinion steering, new assembly installed. Suspension, dialed in 3x over. On and on. My truck was super charged which if you read around the forums people will say that is a no-no for long distance overland travel south. First trip was 15,000 miles in 4 months. My only problem on this trip was the TPS sensor failing in the throttle body. Which by the way had been a problem for a few years before I went south. It is a heat sink issue when you super charge. It had showed it's self a number of times before I left but I could not figure it out and so I foolishly ignored it. It got worse the farther south I went until it was pretty much failing badly by Belize. This was about 6,000 miles into the trip. I replaced the TB and all was well. Finished the trip and got home no more issues at all. To prevent it in the future, I added a TB spacer to help reduce heat sink. Didn't do much else to the truck before the next trip besides add quality air bags and dump the junk air bags I had. Next trip was 10,000 miles, also in 4 months but the actual driving part was less than a month. Not a single problem on the second trip. Now I did both these trips on a set of BFG AT's that had 30,000 on them before the trips. Not a single flat! Now the Taco is not a top of the line Toyota product. A 4-Runner from the same year or a Cruiser is a much higher quality truck. And my truck was at 6,000+lbs for the drives which is way over GVW.
Again, I realize the routes you traveled are rougher than the routes I traveled. No argument there! However, I took a highly modified truck, did 25,000 miles and only had one problem. It was/is a low end Toyota truck compared to others from the same year. The problem I had was there before I left too and is a well known problem with a super charger. So if I can do it in this truck, I believe anybody can do it!
Cheers