Advice on borewell troubleshooting & pump selection in Trichy District, Tamilnadu

I am from Thatheyengarpettai union, Musiri Taluk, Trichy District, Tamilnadu. Located 35KM away from Namakkal and 4KM away from kolli hills. Basically it is a rock area(small mountains).

We used 10HP 20 stages submersible pump  in our 450 feet depth 6 inch borewell. Good water resource was identified at 350 feet depth. We located our initial submersible motor at 360 feet depth and the output was good(more than 2 inches delivery with 2.5inches diameter pipes). It worked fine for two years.
This submersible pump had a problem and it required repair. So we tried to pull out the motor and it was stuck at 250 feet. We used soap oil and urea mix and recovered that motor.

We flushed this borewell and replaced the pump with 5HP 20 stages motor instead of the existing 10HP motor and located this 350 feet depth. That delivery was very bad(.5 inches on 2.5 inch pump).

Currently the same 5HP motor is located at 220 feet and we get more than 1.5 inch delivery on the same pump.

We are unable to trigger out the issue here. The problem is with borewell or motor or pipe diameter.

Can you please advice me the optimal requirement of submerisible pump, pipe diameter and depth to locate this motor?

1. Submerisible pump company people assured that 5HP motor can supply upto 500 feet width. Is it correct ?
2.What is the maximum depth it can supply?
3. 2.5 inch pipe is right choice or not. some people suggest reducing the pipe diameter can help
4. How can we identify the optimal output location of the pumpset in a borewell?Shortage of manpower restrict me to do trial and error method on this location factor. Is there any other method to find out this solution.
5. Is it worth to with 10HP 20 stages motor? or do u have any other recommendation for this.