Is it possible to maintain a reusable django *project* across apps?
A possibility, as suggested, is templating the project which could suffice. However, templating projects would result in a different starting point for every project. Since templates evolve over time there's not one project that starts the same.
Having a baseline throughout all your projects seems only worth pursuing if your big enough as a (development) company and are building enough different projects. A baseline in this case can be a custom python egg or additional django app added to your Django project. Such an app can enforce deployment strategies or help maintain infrastructural dependancies.
For instance, propagating/configuring server information about your infrastructure or other services. Think of db, storage, auth services and other backends. When moving to a different inhouse storage backend or it's new API version, your app can smoothen the transition. If you don't already have added (re-usable) apps to your project specifically to hook up your project to the storage service. 
So, in short, I think the answer to my own question is:
Yes, create reusable apps for this as far as possible but always make sure the solution is not bigger then the problem.
I'm trying to decide whether underneath 'reusable apps' it is doable to maintain a reusable bare project setup as well.
On a side note: I can destroy any of my servers and rebuild it in barely hours as long as I have a (data) backup and a blueprint (in my case saltstack, but it might just as well be puppet, chef or what not).
With a flexible infra, these deployment steps are next:

Create  a virtualenv for the django application
Check out my project (always named project)
My project has a setup.py included. This sets the surroundings:

render settings files based on yaml data and templates
Possibly loads fixtures when needed
When in production, it renders apache config
etc

After that, as git submodules, you can plug your reusable apps to end up with a running webapplication.

With quite a lot of intelligency built in the bare project base structure I ended up with my original question.
I'm wondering if the project baseline is maintainable as a cross (Web)Application seperate git repo. Or does the project structure itself have to much specific moving parts related to the (Web)Application as a whole?
E.g: pluggable apps go in INSTALLED_APPS, etc and always ending up with to much related/changing data.
Hope it's clear. Looking forward to you comments