I use to live in Ohio and believe me, moving to San Diego was the best decision of my life. I haven't regretted a minute of it.
San Diego is one of the nicest cities in the country. It's a major tourist destination and there are tons of things to do. With 70 miles of beautiful beaches, countless parks and gardens, major league and college sports, dozens of golf courses, world class museums, Tony Award winning theater, great cuisine, best weather in the country, high tech industry, major universities, and the best zoo in the world, it's my choice as THE place to live and play in the USA.
Finding work will be entirely dependent on the type of job you are looking for. Construction jobs are hard to find but hospitality, health care, and high tech are industries where jobs can be found. Current county unemployment rate is 6.8%, which is lower than the state's over all rate (8.9%), and it's getting better. Ohio has a 7.5% unemployment rate.
Here is a cost of living comparison calculator. San Diego is about 28% more expensive, so $20 / hour is more like $15 / hour. The calculator will break things down by category.
http://www.bankrate.com/calculators/savings/moving-cost-of-living-calculator.aspx
The big sticker shock is housing. People expect to pay 30%-35% of their income on housing. Everyone wants to like within 50 miles of the coast and that is what drives up the cost.
As for housing, besides Escondido, look at the San Marcos and Vista areas. They are a little closer to the coast and summer temperatures will be a lot milder. When it's in the 90's in Escondido it will only be in the 80's there.
Check out these sites for more info
http://www.sandiego.org/nav/Visitors
http://thebestplacesinsandiego.com/