Pia-Louise,
I hope they will germinate for you. Since you are in Zone 8A and no winter conditions you're best with controlled stratification. For the rose seeds, you might want to try soaking in H2O2, and stratify cool. I would be tempted to use bottom heat after stratification. The floaters when soaking are probably sterile and throw them out. Or, if you have lots of seeds, experiment with soaking in H2O2, them move to the baggy and refrigerate for a few days, then put the baggy in the freezer for a few days, then thaw and sow them and provide bottom heat. You may want to ask Zuzu about rose propagation from seed. She may have some extra or different advice.
Are you thinking of nicking and soak in H2O2 for the Acer?
