You should put an optional auto zap option that reminds people to zap sats to the app developer and to the Zapstore every time an app is downloaded and/or updated, and encourage people to set it up when the Zapstore is first run.

Indeed!

In the pipeline, yes Also paid apps

Do you have a product in mind you'd want paying customers for?

Yes a Zapstore Premium (for both devs and users) and a few other monetization ideas