1 - I think Parameter service access should be separate from admins. should have it's own access that can be added to any individual, position, etc.
2 - Since revit uses GUID's, there doesn't seem to be any reason we can't edit names once a parameter is put in. There are a number of reasons this may want to happen, but what we don't want is to break all our families by making fresh new parameters. If there are issues with this in families despite the GUID, then this service should solve that otherwise it's not much different than just a shared parameter. Additionally making the switch from project parameters to shared parameters for all standard parameters isn't as feasible if the name cannot be edited.
3 - Not sure whether this is temporary or permanent, but you cannot add any shared parameters you have already added with the same GUID. This becomes an issue (especially if just testing) if you archive a set of parameters, then go and try to re-import them. Maybe add a warning and even a list of which parameters already exist and see both versions, but to not be able to re-upload just confirms this service isn't ready yet. (even if it takes time, it's currently been 30 minutes and I still can't re-upload my shared parameter file.) another solution would be to allow access on ACC to permanently delete archived parameters
4 - It would be nice if the service could manage parameters in a way that they can "Sync" changes but only if activated. This way if something changes in the cloud it can be adjusted in a project IF we choose to sync.
The real benefit of having a cloud service needs to be ease of all parameter management, being able to easily find parameters, edit them, and have them, and have collections that can be accessed. Additionally, these collections should be one click loadable to a project. This could be done simply by have a check all checkbox above all the checkboxes.