You are totally off on your assumptions about the insurance industry. The primary job of an adjuster is to close to file. They do not want to spend hours hemming and hawing over minor bullshit. Show them a reciept and they are going to pay. Use reasonable estimates and they are going to pay.
Start claiming that as a landscaper you have 10 Armani suits in your closet and they are going to red flag and say show me some reciepts or credit cards. The same criteria holds true for your taxes. You want want the write off, go ahead and take it. We ask for recipts, you better have them or yuo face penalties.
The problesm that many older folks will run into is that they have old policies that do not have an inflation adjustment on them. This means that they become underinsured over time. It also means that they were not paying sufficient premiums for the coverage in this type of incident.
I would argue that this is one of the very reasons I choose to buy everything on credit card. I have a paper trail for all of my purchases. Additionally a digital camera or a camcorder is can be used to take pictures of your place. It take s less than an hour to do this and you can put this on a memory chip and hand it to your agent. Again insurance companies just want to keep the file moving forward.