VEVOR 3/4" PEX Tubing 300Ft Non-Barrier PEX Pipe Blue Pex-b Tube Coil for Hot and Cold Water Plumbing Open Loop Radiant Floor Heating System PEX Tubing (3/4" Non-Barrier, 300Ft/Blue)

Yes, This should work well for your supply line from the well pump to your house.

Yes it definitely will. Be sure to protect the pipe with a sleeve or insulation when it's buried.

I would say that you would need more volume than just a three-quarter pipe

It should be fine to use it outdoors, but will need insulated if used during winter.

I use mine outdoors. I’m planning on burying it.

I've had mine buried outdoors for 3 years now. Works fine. I don't know about being exposed to sun light though.