apoid I did something similar for my setup and it's been working pretty well. I don't really have any play store dependent apps and pretty much go without push notifications so I keep my work profile turned off basically all the time.
- Do you think this is a good way for my needs?
Yep, it should work fine.
- How to install the Google Apps exactly? Clone the Graphene “Apps”-App with Shelter to the Work Profile? Or clone the 3 Google Services Apps (Google Play Store etc.) directly to the Work profile? But how to update these 3 Google Services apps then?
Shelter gives you the ability to clone apps between the work and main profile so the starting point is cloning the "Apps " app provided by GOS to the work profile and then installing the needed Google services there. I actually have some paid Play apps I bought years ago that work fine in the main profile without Play Services or the store so I update them in the work profile and then clone them back to main. Aurora in the main profile can tell me when they need updated but can't update them since they are paid apps and I'm not logging into any Google services on my main profile.
- How to install (and update) the google Camera to the main profile? As I tried “Gcam Services Provider” can’t be installed due to the Google Play Services installation in the work profile.
In my main profile I installed GSF only with no permissions and then installed the GCam app (with no network permissions) via Aurora and this works fine. It can still update via Aurora just fine and does not need anything other than GSF to run properly.
So far my only headache with this was finding out that Signal installed in my main profile could see that Play Services was installed in the work profile and so didn't want to setup using websockets for notifications and would error out on setup until I removed all google apps from my work profile. Other than this little one time setup oddity everything seems to be working perfectly. If you set up Signal before doing anything with a work profile you won't have this problem.