1994 Honda Accord 94 Honda Accord interior Electrical issue

Since I bought my car about 2 months ago I have been having electrical problems inside of the car. Here are some electrical issues.

1. When I start my car the sometimes radio dont work so to get it to work I have to turn the headlights on or turn signals on.

2. Usually just my back speakers work until I either turn my headlights on or put signals on or open the passenger door then close it then all speakers will work.

3. Car gets bad radio reception when I step on the brake pedal to hard and sometimes looses signal until I step on it hard again.

4. When I turn the dome light on automatic mode so when u open the car door the light turns on. Instead of it just turning on it stays on and dont turn off unless you just flip the switch to off mode. And when the dome light is on there is a buzzing/ humming either from dash or speakers.

5. Sometimes on the dash it shows that the passenger door is open even tho it isn't.