I rang various insurance providers, including dad's current one and my own, who would not provide 'extended insurance' for dad's unoccupied house (by extended, they mean including theft and vandalism, and 'escape of water' - the kinds of cover you normally expect from house & contents insurance).
Insurance that included theft etc could only be provided by non-standard insurance agencies, and the quotes varied wildly! The highest quote was nearly £700 for a 6-month period, and the one I took was £440 for a 12 month period! Strangely, they were both underwritten by the same insurers... so how does that work???! Anyway, the moral of the tale is to spend some time ringing round to find the best deal.
As for financial advice, Age UK suggested I speak to the office of the public guardian for pointers in the right direction. They thought it would be worth asking the OPG who should pay for the advice (if we go that route), and not assume it should come from my dad's money. If we had to pay for advice about my dad's accounts then I'm afraid we wouldn't seek advice... we can't afford it... and would seem very unfair to me :-/. There are some free advice services out there, including Pickles link, so I'll try those first.
Clearing the contents --- I'm less stressed about this now, thanks to your lovely support 
. It's all very emotional and that clouded my thoughts for a while. Also, I've spoken to a care worker who said that it's ok to dispose of any item as we see fit, as long as it isn't worth more than about £500. Anything worth more than that is considered 'valuable' and should either have proof that it belongs to me or my sister, or sold on dad's behalf to raise funds. Not selling the house at market value, not selling valuable items, or taking valuable items without explicit permission can be considered deprivation of assets. Anyway, I feel better knowing this because I like to work with numbers and doubt very much that any single item in the house, whoever it belongs to, is worth more than the £500 cap. The care worker also said it was highly unlikely that it would ever be chased up anyway, but it's still worth making some record of what's in the house (I've taken photos).
I hope that helps anyone else going through this. We've decided to delay the sale of the house and take some time clearing it; it was starting to feel totally overwhelming!
