Searching for knowledge on my new 4runner

Hello, new here and looking for some advice on things. Just purchased this 1990 4runner with a V6/Auto.
No rust and body is in good condition, interior is also on surprisingly good condition, with a few cracks in the dash. Still registered, and clean titled, and I paid 1000$ for it.

The only major issue was the auto was stuck in third. Swapped out all the solenoids and it starts up drives no issues with the exception of some loose ball joints. 4L works along with the auto lockers. And no leaks, besides a pinhole in the radiator.

1. The AC lost charge due to a bad charge valve. It's 400$ to fill with R12, or should I consider converting the compressor?

2. I am going to add a trans cooler in-between the radiator and the ac condenser. Is that a decent spot? Im keeping the clutch fan at the moment.

3. The front passenger tire has negative camber, and it pulls to the right. I'm replacing all the ball joints as there's considerable slop and It appears the eccentrics are maxed out trying to correct it. Is this likely bad control arm bushings affecting the camber?

4. Parking Brake seems disconnected, is there a common failure spot to check?

Overall I'm pleased with it. Once I have all the small things buttoned up. It going to be going camping all sorts of places. Next year I'll consider putting a small lift and a winch so I can do some slightly more rough stuff with it.

Also any must do mods to improve reliability. Probably an unpopular opinion but the 3.0 is doing just fine at the moment.