Name: tarev San Joaquin County, CA (Zone 9b) Give PEACE a chance!
I only have a few Hoyas, but there is one I grow indoors year round, blooms intermittently through out the year. My Hoya shooting star, but of your three requirements, it does not have any fragrance. It certainly enjoys cooler conditions, likes to be in standing water.
As to the sugary sap, yes it does become a bit messy, so I have an oversized tray under the plant to start catching the sticky droplets and to catch the blooms when it starts spitting it out as the blooms fade.
My other hoyas seem to prefer the part-shade warmth outdoors to be able to bloom.
