Yes, you can use Google Camera with all the processing if you install google camera and google photos. It prompts you to also install google VR services, which works without network permission, to get additional features.
I have compared them side by side, and outside of minor differences in video processing, I could not make much of a difference between photos clicked on GOS and Google's Android using the google camera app. The color charts, noise, etc. are pretty similar in similar conditions. The default app lacks the same level of processing, but is decent in a pinch.
On the transition, I recommend starting by using all the services you currently do and then slowly moving past them, instead of trying to force several major changes at the same time.