Regards the two 110vac circuits on a single 220vac line. Every main breaker box that I've worked with in my personal experience, does exactly what you've said can't be done. The utility supplies anywhere from 204 up to 220vac. We all call it "220" when it most often isn't. This line has two "high" sides and a neutral.
The two high sides are 180 degrees out of phase with eachother. The breaker box splits this into many 110vac (102-110) circuits. Each of the two high sides measured to ground will be approximately one half of whatever the utility company is providing to the house (204-220).