> 1. Is it really so complicated?

Depends. Are you a >500 Developer org with many services? Then it's easy compared to what's out there. Anything less than that I'd say it's complex and you'd be better off using a PaaS

> 2. Is that complexity incidental or essential?

Depends. If you're going to do simple things forever then it's an overkill. But if you expect to grow in unknown ways in the future and don't want to waste your time doing bunch of migrations in the future then it's essential.

> 3. Could we get away with a simpler set of abstractions for 90% of applications?

Maybe? Heroku, AppEngine, CloudFoundry tried, but didn't go too far. Let's see what new crop of PaaS offerings are able to do