Hello all, not sure if this is the right place to ask do forgive me if it isn’t. I have a Standard Persona 2019. I was unimpressed with the audio quality so I am making it a hobby to upgrade my stereo. However there is just too many options and I need help on a few aspects.

My situation
-No rear Speaker (not available on variant)
-Car still under warranty
-No sound treatment yet

My aim:
-Keep the stock non-touch screen head unit
-Focusing on clarity and staging.
-Medium to slighty loud listening volume.

What I have in my shopping cart
-Edifier CW810 (Sub)
-8 inch Active Subwoofer
-Power Input: DC 11v-16v
-Has amplifier circuit

-Focal 165 AS Access (Front)
-6.5”
-Component Speakers
-RMS60 watts
-Comes with crossovers

-Edifier S651A
-6.5”
-Coaxial
-Power rated at 50watts

My concerns:
1. Do I need amplifiers/dsp for the four speakers?
2. Is the subwoofer enough to reproduce good low end?
3. The sub has on board amp, do I still need a monoblock?
4. Will any of the needed process void my warranty?
6. Do you know any accessories shop with good installation practice?
7. Anything else I need to know?

Thanks for the comment. Zero5177 gave some good cost saving measures. So now I’m considering moving the stock speakers to the back, and using the extra budget to change my HU. So now my setup looks like:

-Kenwood DDX6016BT
-50w x 4 output

-Hertz DCX165.3 (Front)
-Coaxial
-peak 120w
-Continuous 60W

Stock speakers (Back)

I’m guessing the 60W is a bit on the higher side, so I’m going to need a 2 channel amp.

Leon 2 channel, class AB amplifier.

Forgot to mention the edifier subs