In terms of your grandfather living there as long as he's not the owner having a dwelling fire/rental property insurance policy is appropriate.As @Greg Scott pointed out he should have a renters insurance policy whether or not he's actually paying rent.In terms of liability coverage, that depends on what you have to protect so there's no one-size fits all approach.

If you watch the video of the hearing you can experience the series of events that lead to the unique misfortune of this deal.

In all of my units I include a private workspace that's in a room with a door that closes (important for video calls), a comfy desk chair, monitor, keyboard, mouse, and hdmi cables.

In addition to the above video, look up Jason Velie, the trailer park king.

Alecia, I was just watching a Youtube video about this, I really appreciate the feed back 

Bright Investor was  mentioned in a yu tube video.

In fact, the judge may be far more lenient to the tenant.I never charge something against a deposit unless I have visual proof (pictures, video, documents) to back my claim.

If your contract doesn’t state terms for additional access, then I understand his concern, maybe ask if you can video the interior, although most tenants won’t want that.

Find Brandon's videos on YouTube for the "four square" method of analyzing homes and practice.

To finally use the knowledge I’ve been building up with the bigger pockets podcasts and various YouTube videos has got me pumped.