Seeking advice on pool equipment/plumping based on attached design

[Mohannad Al-Awad]

Greetings everyone,

We are in the stage of signing with a pool contractor.

I have some concerns regarding the contractor's recommendations with regards to the following:
1- Number and size (e.g. 2", 2.5", 3", or 4") of the overflow channel drains (i.e. by gravity) [contractor's recommendation: 2x2.5" only];
2- Kind and size (i.e. horsepower) of pool pump [contractor's recommendation: Pentair SuperFlo 2HP];
3- Number of water supply outlets [contractor's recommendation: 8 only];
4- Ability to group electric junction boxes along the pool fence [contractor's recommendation: separate for and directly above each lighting unit].

What is your recommendation on the above points?

The last thing that I want is to have the water from the overflow channel to spill into the garden with every person jumping into the main pool. Also, I am worried if the pool pump can filter the water from both the pool and the waterfall.

Our pool is an outdoor infinity/overflow pool in a harsh weather with the following spec summary:
1- The main pool section (31.2m3 / 8242gal) ends with an infinity edge (i.e. a short waterfall) into the front pool section;
2- The front pool (1.65m3 / 436gal) overflows into the overflow channel (1m3 / 264gal);
3- The balance tank (6m3 / 1585gal) is less then 1m / 3.3ft from the edge of the overflow channel and less than 8m / 26ft from the equipment/pump room;
4- We would like also to connect the pool filtration system with our fence waterfall (less than 5m / 17ft wide and less than 3m / 10ft high) if possible.

Thank you all!

Pool.pdf

[RDspaguy]

The thing to remember is that all of these factors are not separate, they are part of a system, and changing one thing can necessitate changing the rest. Your builders recommendations are for that system, and I'd suggest you follow them. 

For example, say you want a bigger pump. Now you need bigger, or more, pipes/returns to handle the increased water flow, and a bigger filter and heater to handle the higher pressure, or you just burn up your bigger pump, or blow apart your heater gaskets.