Power outages may be caused by weather, line or equipment problems, or too much demand on the system. Regardless of the reason for an outage, you will still contact your local utility company to repair or restore your electric service. Outages are generally caused by problems with the wires, not the power plants themselves. Storms may cause wires to go down, or sometimes the wires simply fail to operate properly. In these situations your utility will still fix the problem regardless of whether or not it is your supplier.
Electricity is electricity, regardless of how it's generated or who generates it.
You will be billed based on your usage, just as you are now. Because your electricity usage can be measured, you are still supporting the supplier of your choice. If you choose to become a delivery services customer, expect changes in how you are billed. You may receive one bill from the new supplier, or you may receive separate bills - one from the electric supplier and one from the local utility company that delivers electricity to you. Specific questions about billing should be directed to the company you choose as your electric supplier.