IanML

Before you pay for new shocks, why not just remove the current ones and see if that restores the level. If it does not, it's not the shocks.

It will adversely affect the 4x4 if the center diff is locked (assuming your RAV4 has one - mine does not) and the tyres are not the same outside diameter. Nothing else that I know of.

I would put your newer tires on the front, and you should be ok with a different design. Just don't mix cross-ply and radial.

Perhaps one of the front springs is not seated correctly since the shocks were changed. It's hard to imagine how that could upset the rear without showing some effect at the front, but the extra weight under the bonnet may be relevant. My money is still on an unseated rear spring. Should be easy to check by undoing the bottom of the passenger side shock, jacking up the body on that side until the spring just becomes mobile, and waggling it around to see if you can increase the clearance. There are "insulators" (seating disks) shown in the parts list as fitting above and beneath the spring - that (or its absence) may be playing a part.

Sometimes, a spring does not seat correctly in the cup, resulting in apparent increase in loaded length.

It may not be easy, but can you measure the loaded length of each of the rear springs? A comparison should tell you whether the discrepancy is due to the loaded length (i.e. the spring rates are different/the sides are unevenly loaded) or is due to the body. If it's the former, swap the springs left to right, and if it's still down on the same side, it must be the weight.

Body twisted in a prang?

That seems right to me. The video clearly shows the engine shaft being turned and the final drive shaft rotating as a result. And, of course, MG1 cannot both drive and generate simultaneously! The diagram is also somewhat misleading, because it does not make clear that the motor and generator boxes are actually both MGs.

It is very clever - essentially, whether MG1 assists the engine, or not, depends on the speed of the engine. The engine does couple to the final drive through the epicyclic geartrain, but it can declutch for a pure EV mode. MG2 has more than twice the power of MG1, and it seems the reason for the two is for control flexibility and efficiency.

It's very complicated, but I've found this video, which does give some insight - it's the latest Prius 610, but I imagine the principles are the same for the RAV4.

That description of the drivetrain does not accord with the one given at https://www.toyota-global.com/innovation/environmental_technology/technology_file/hybrid/hybridsystem.html, which shows the power split device feeding the gearbox & axle, as well as a generator which is not connected to the axle, so cannot function as a motor. A separate motor is shown connected to the axle, which could, therefore, also function as a generator in regenerative mode. I wonder which is correct?

Perhaps the individual items are priced as parts only - no labour to apply them?

That sounds good, but I'm doubtful it's a good indication unless you can be sure that the battery charge state was the same at beginning and end.

Perhaps they sold you a refurbishment kit.

Happened to me recently, and without towing anything. You may find this post interesting.