I have a c220 too, so here are my definite answers:
1. Does the C220 really only require 0.7 quarts of fluid?
No, it's about 1.1 quarts
2. Does the C220 have a crush washer that needs to be replaced or are there just drain and fill plugs?
No, both fill and drain plugs do not have any crush washer. They are simply two 14mm Allen bolts.
Be sure to get a breaker bar and remove the fill plug first.