Is it "safe" to do manual optimizations in the postgres db when using Prisma? Adding indexes to fields etc..? What about combining prisma with direct postgres access in my apollo prisma graphql server..?

I think you should be good for now. But these features is in our roadmap, see datamodel 1.1: https://github.com/prisma/prisma/issues/3408

Thanks that looks like it should cover most of my needs 👍. Maybe except for row-level-restrictions and sepearate users for a single db mutli-tenant setup, which I'm researching atm..