Answer 1

1. some Linux distros are available for raspberry pi
2. you can code with your rapberry
3. raspberry is ARM, i don't know if theres a Windows 10 ARM version for raspberry pi, but i believe theres none win10 arm pi version

Answer 2

yes and yes
to program on pi just go to programing then go to python3 and click new file
and to code from different devices https://www.chiark.greenend.org.uk/~sgtatham/putty/latest.html
and click 32 bit fwi

Answer 3

Yes, you can. There is an IoT version of Windows 10 for the Pi available on the downloads page of the raspberry pi website. You can also use Raspian (the default OS for the Pi) and code in Python. Good luck!