I am having issues related to the fuel pressure in my Land Cruiser 200 series. It is a 2010 model with a 4.7 v8 (2uz-fe) and a 140 ltrs fuel capacity(petrol). It is a gcc spec.

Some time back I took the car on a road trip. On one of the stops we took, some small animal ( probably a cat ) somehow climbed into the exhaust of the car and got stuck in there. I was unaware of the issue and continued driving but felt the performance was a bit sluggish and the engine was heating a little bit on prolonged drives. But this was during summer and I felt it must be the heat which is causing so. This was until I stopped at a gas station to fill up fuel and as soon as I left the gas station with the tank full, someone stopped me to show that the petrol was leaking straight from the fuel tank with full force.

The leak stopped eventually after a few minutes but by then the fuel tank was almost at half. I took the car to the nearest available garage on the highway and he figured one of the fuel lines had a hole in it and was leaking. As a DIY fix, he cut the line and replaced that portion with a rubber hose and tied it up. The leak stopped.

Fast-forward when I reached home I took it to a local repair shop where he checked and told me the fuel tank had also got a hole on the upper end. I replaced it with a second-hand fuel tank. Then he told me that the muffler of the car was leaking the exhaust gas which was shooting directly on the fuel tank and the fuel line. This was causing them to melt down. I replaced the muffler and the DIY rubber hoses which were coming from the fuel pump. This is when I found the animal just burnt and stuck in the exhaust pipe which I cleaned as well. Also changed the fuel filter.

Now the car runs and drives fine but the performance is not the same as before. Especially when the fuel tank is filled more than half or three quarters, the engine feels reluctant to accelerate. When the fuel level is close to empty, the car runs better. I also replaced the purge valve of the car from the eval system but still no avail. 

I have spent too much time, money and effort to fix it but cannot seem to figure out the cause.
I checked with a few other mechanics and some said it may be the fuel pump while some said the carbon canister may need cleaning. 
I cannot take any more random shots at this and really need some concrete advice.

If someone has an idea as to what this could be please let me know, I would really appreciate it.