Help to made e-bike

[Smurf]

Hi.
I want build e-bike. I am around 60kg. My past bulild was e-skate and drone.
Plan is bought E-bike KIT from Aliexpress, or Ebay. __Example__ At first for Job (44km), enjoy and others..
Plan:

Type: Mtb
Power: 350W-500W?
Voltage: 36V
Distance: around 40-44 km
Speed: 30+ km/h
Motor: Rear Hub
Wheel: 26inch?
Throttle: half or full
PAS and e-brake: ?

I will need your opinions and some explanations about parts which not understand good.

1) I saw videos where is speed of 350W and 500W same like 20mph. Which power you reccomend me for my speed (above)?

2) First what I don't understand good is PAS. On some video throtle not start before pedal not mowing. I am comfused,
because on other videos throttle start immediately on hand turn (without move pedal), what is true? Talking about HUB motor.

3)What means for a) Rear Rotate Wheel Motor or b) Rotate Flaywheel ?
__Example__

4) Is there possible when not using (like out of battery), normally run bike with pedals, what need for that?

 

[ade]

500watt? it will soon be not enough power. i recommend a 750w bafang midrive

 

[ade]

lots of research on the controller too, they are all different. the battery is simple make sure you go for more than you might need, keeping in mind the batteries holding capacity drops after many recharges. aim for waterproof equipment too, waterproof battery covers are easy to find but come in different sizes. obtain a couple of proper battery mounts and not mounting the battery directly to the bottle mount bolts. also , go for big brakes , as the bike will go through the pads faster due to bigger deceleration