Governance, Retention Policies, Records Management - how are you doing it?

I can answer some of this.

1. My org doesn't have a process for this yet.
2. No
3. For site closure and deletion, we convert everything into a document form (even calendars or task lists via Export to Excel) and pack it up into a folder to go to a designated archive document library.
4. You could archive an entire site, but I wouldn't personally recommend it--you'd have to redeploy it to dig through it, and I feel it's just better to convert everything to a document form so anyone can get to it at any time. Keeping in mind that everything has to end up a document helps us keep our site sprawl from getting too out of hand, particularly for project sites.
5. Implement structure and processes for when to use site collections or sites, who can make them, and what each one should do. Train some people to be power users ASAP or you'll be alone on your SharePoint journey.
6. N/A
7. No
8. No