Can I use a development copy of the database for development and easily swap the resources over to the production database for staging and release?
Yes! This is available on the Startup Plan!
This option can be found in the resource setup (I believe you need to save before this is available):
Then inside an application you can toggle between the two:
It’s important to note that this toggle only controls a flag which is stored locally, so changing from production to staging will not globally alter your apps data source.