A. Every time you need to do any electrical work, Electricity is very dangerous and could cause death.
A. Every time your breaker is getting hot, your appliance load is making the breaker trip, you have your breaker using more than 80% of the capacity, If you need to add more lights or need to have an appliance that has ampacity more than 50% of the size of the breaker to be plugged on it.
A. Separated some of the loads to a new circuit.
A. First, you need to organize all cables and add more receptacles with an extra circuit so you can avoid overload and also add a surge protection.
A. Yes
A. Depends if your lamp or light bulbs are dimmable.
A. Overload. You probably have too many lights and appliance plug on the same circuit creating heat on your wire and pass to your breaker.
A. You need to check if the size of the outlet is enough to have all wires. Also, check if any of the wires still have the original color or if they have any type of burned color, check if the outlet is properly secured in place, and check if the outlet is bonded with equipment grounding. Additionally, you can check if the box is rated for the weight to be used.