Regarding the issues you had issues with the bundle, you’ll need to adapt it for your environment which will have the various space names, osd devices, etc. Bundles are quite powerful and the documentation is worth a read, but it can encapsulate the various constraints, the network space bindings, config, etc. I understand you’re just trying to get it deployed, but you might find it easier iterating over a bundle and using that for deployment.
The ‘cannot use space “alpha” as deployment target: no subnets’ error seems that it relates to this post in that you need a default space binding as well. You should be able to specify this as in the bundle with the space name being “”, and per that posting there’s a model config parameter as well.
An additional point based on the config.yaml that you’ve posted is that the ceph-public-network and ceph-cluster-network charm options will override the network bindings that you specify. It would work in your case as the networks are the same, but you shouldn’t really need to use those config options if you are using spaces.