Sorry to hear about your brother's plight. As a homeowner, the insurance company 'expects' you to take mitigating measures to prevent any further damage. So, if what you want to do will reduce/mitigate any further damage, it would be reasonable to remove more 'stuff'. Since the Adjuster is coming, listen to what they have to say. Just DON'T take a check as FINAL PAYMENT! You might want to consider hiring your OWN adjuster for an estimate. (Look around the Yellow Pages, or ask your bank/mortgage company for a reference, or ask your Realtor. They're out there.) In doing this, you have someone who's actually working for you. SUre, the insurance co. is 'on your side' but it's their job to keep costs down too. Your own, private adjuster doesn't care about what it will cost to fix the job. He has no interest in that like the ins. co. does. He's paid a fee for his work and he's done w/it.
Do ask the ins. co. what you should do to further mitigate any more damage. If the roof is structurally sound, they might recommend, well, that the roof be done first. They may also recommend that you move your belongings into storage too. Ask about who's gonna pay for all that. Just make sure that WHATEVER you sign, it DOESN'T say ANYTHING about being a final payment. DO take the time to read what you're handed, and if it's not clear what you're reading, ask while the Adjuster is there. There's no need to tell the ins. co. Adjuster that you plan on hiring your own Adjuster. The biggest 'thing' that can happen here is that 'things' may look OK today but NOT look ok when it comes time to do repairs. For example, you might incur an expense to have an undamaged room repainted because the damaged rooms will 'look different'. If the family room's paint is 10 years old, it WON'T match the NEW paint in the adjoining rooms (assuming they're to be the same color.) Make sure 'things' like this are allowable by your ins. co.. Use this 'thing' as an example.
If you have more specific questions, post up. My best to ya and hope this helps.
PS: Hiring your own, personal Adjuster is worth a few hundered $$$. Just do it. (No one else is 'working for you' othere than the repair people, and THEY'RE only giving you the bill.)