i've just recently replaced the door lock mechanism on my driver's side door so i'm familiar with how it all works. the inside handle goes via a cable directly to the mechanism and should open the door without the need for current. i believe it to be the "failsafe," i.e. it should always work.
the fact that you cannot open your door from the inside is the most puzzling. is there any resistance on the handle or is it completely loose? this will tell us the state of the cable.

the fact that your window works with no key is also bizarre. it shouldn't.

i'm not sure if you can remove the door panel with the door closed. it might be possible but would be a PITA. but that might be your only solution.