Yes, you should get a quote or an estimate from an electrician. Most electricians offer free estimates or quotes. When getting quotes, do your research and verify each electrician’s license. Get quotes from three different electricians to compare. If the prices or items listed appear different on the quotes, ask the electrician to clarify. Learning as much as you can about the electrical work you want done will help you get the most accurate estimate. 

No, it is not safe to use an outlet that sparked. A spark from an outlet could indicate a short circuit, loose or frayed wiring, or other serious damage. Continuing to use an outlet that sparks can increase the risk of electrical shock, electrical fires, and other hazards. It's important to turn off the power to the outlet at the circuit breaker if possible and avoid using the outlet until a licensed electrician has inspected and repaired it.

Yes, but our analogy with the water hose doesn’t really work here. You see, electrical flow isn’t constant: It ebbs and flows like waves, coming in pulses of power. Hertz measures the rate of change in the flow of electricity, or how often it ebbs and flows. For example, 60Hz means that the electrons pulse through wiring 60 times per second. When they are pulsing, they’re in a brief retreat. Almost all United States equipment is rated for 60Hz.

A larger heater requires a larger breaker—unless there’s one already installed. The longer answer to this question is more nuanced. Do you place demands on the heater at the same time as running other heavy-duty appliances like ovens and washing machines? Do you live in an older home that may not have considered the higher electrical demands we have now? Breakers need to be sized at 125% of the load. To find that load, you should call a local electrical pro.