I'm not Dr Dirr, but as a professional shrub breeder I can answer your questions. - Pollination is usually done by hand, as you mention. - Germination requirements are different for every species. Some are easy, you just sow them in a greenhouse or cold frame at the end of winter, and they'll readily germinate. But others require stratification, so you have to keep them cool and moist over winter. The most difficult ones need warm stratification and cold stratification, so they usually have to be in soil for a year to germinate. - The number of years until introduction mainly depends on the number of years it takes for a seedling to flower. For the ones that can already flower in their first or second year, the entire procedure from crossing to introduction takes about 7-9 years. If the selection procedure has to be strict, because there are already a lot of cultivars available (like for roses), its about 10-11 years. But it can take 12-15 years if plants take a long time until first flowers (7 years for Pieris japonica!), or are slow to propagate.

That was in Athens, GA