Hi all!
Thank you very much for all your input over the last week. I have now created a new draft, in which I have tried to address you concerns and suggestions:
https://meta.wikimedia.org/wiki/Wikidata/Notes/Inclusion_syntax
The major change is that items are no longer explicitly passed around as data objects, and the use of templates is not required. Instead, item properties are addressed directly, optionally also using the ID of the item to access.
Please have a new draft and let me know what you think!
Thanks Daniel