Creating inter-relationships between nodes

I’d like to be able to create inter-relationships between nodes, to better reflect the kinds of usage I see in my users, please.

Some examples:
* A single venue/location may house several businesses – eg. ‘hot-desking’ – but those same users/businesses may make use of other premises at times, eg. the local library.
* Associating Events to Places – the places might be static, but I’d like to be able to provide a calendar of events for that Place next to the profile
* Sub-Places (Place A, Room X) & Sub-Events (e.g. Conference with discrete workshops)
* I’ll be looking at the Groups plug-in, to see if Places can be Claimed by groups, rather than individuals

There may be Events that are not associated with a particular Place – such as a street faire – and that’s fine, but I’d like to provide as comprehensive information in results/profile pages as I can.