I also had the 1.5 ton jack to use at the race track and it lasted about a year before failing. I apprehensively bought their 3 ton aluminum low profile jack but purchased the warranty this time. It is still working 4+ years later and is much better controlling lowering speed and raises higher.
I wouldn't go off road and go slow over bumps. You don't want that c-clip to come loose.
Once you fix it, expect your front lift to be reduced quite a bit ;)
I hope I'm wrong, but looking at your pics, it looks like the spring seat/cup is upside down on the front? The clip should be completely enclosed by the seat/cup and not visible at all.
Pretty straight forward, I don't know how you could install the shocks incorrectly? I just made note of which direction the pigtails were facing on the stock springs and installed the same.
Couldn't get mine off either, so I had to pump it out. I had a 30+" breaker bar, but with the wheels on the ground, I just didn't have enough room to make use of it.
I just bought a pretty much identical 4Runner six weeks ago with 115k miles for $16k, with all service records at a dealer and the timing belt done at 85k. I think that's a great price.