EU centric noob questions about my Gen 2 T4

Some of you may have seen my other thread here about taking ownership of my Dad's Prius. Rather than post my questions there, I felt they warranted their own thread. If this was in error, mods please let me know.
As this forum tends to skew US, I'm hoping more EU owners could chime in and confirm some things, as I have done some searching and can't seem to get concrete info. For context, I'm coming over from a VW Golf Mk5 1.9L TDi.

Car is a 2008 Gen 2 T4 spec with approx 130k miles/209k km

So here goes:

1. Can someone confirm that my fuel tank is NOT a bladder, and what its capacity is? I'm guessing about 40 litres. That being the case, can I further assume that with my fuel gauge having 10 blocks, each block is approx 4 litres?
2. This being my first hybrid/automatic, one thing I'm missing coming from a 1.9 TDi is that pickup in the acceleration, I know I won't get that in the Prius but what weirds me out a bit is when the auto transmission decides to change up seemingly at high revs. I've kinda had the habit in manual cars to change gears at 1000 rpm marks (3rd at 3000 and so on) so is this high RPM change typical?
3. An extension of Q2. I get the feeling that I'll have to change my driving style in order to reap the benefits of Prius ownership and with it both being a hybrid/auto I won't get the satisfaction of the quick pickup that a turbo-diesel/manual brings....but surely I won't have to drive like my Dad? I'm no boy racer but I'm also not a Grandpa.
4. I don't have a reverse camera, but I'm interested in fitting one. I've found a used OEM part for sale locally for €30 and considering grabbing it, but I've seen conflicting info regarding the wiring harness being present in an EU Gen 2 2008 T4. I have no interest in fitting the camera if the harness isn't present. If I remove the boot door panel what do I need to look for to see if it's there?
5. I miss not having Bluetooth audio/phone. I can get by temporarily with a BT adaptor in the Aux port, but I've got a single din Pioneer BT stereo that I could replace the stock head unit with, but will it play nicely with the JBL amp, MFD, steering wheel controls, and camera should I fit it?
6. Fuel economy: I have only driven the car for a few days and I'm averaging 5.5 to 6 litres per 100 km (47 to 50 imperial mpg) and that's driving sedately. this seems to be no better than my Golf. is that typical?
7. Is there any way to check the capacity/health of the HV battery? at 130k miles should I be worried about its lifespan?

Thank you for indulging me!

 

Thanks! That's a good start at least!

 

Brilliant post Chapman!

Now if I can get more info on my reverse cam harness. I think that's next on my to do list.

 

Just bumping this thread in case anyone can help me with below:

4. I don't have a reverse camera, but I'm interested in fitting one. I've found a used OEM part for sale locally for €30 and considering grabbing it, but I've seen conflicting info regarding the wiring harness being present in an EU Gen 2 2008 T4. I have no interest in fitting the camera if the harness isn't present. If I remove the boot door panel what do I need to look for to see if it's there?