1) The HUGE issue (I have experienced this one), is when a company says they will give insurance, then no one comes to check the house until after closing, they dont like something (like your roof) and your only option is a new expensive roof with you paying full cost by yourself, finding a new insurance company or forced insurance being put on the house at a very high rate. Talk to your insurance company NOW and make sure that if they need someone to physically look at the house, thst has happened.
2). The insurance company is asking you for a copy of the building inspection report rather than sending someone out yo look at the home in order to establish a "base line" for the home's condition - then if you file a claim later, they will look at the report and say, oh the roof had only five years left so we are adjusting what we are paying you accordingly, or this area already had some damage so we are adjusting our payment and not paying for that portion of the repair.
I would talk to some other insurance companies and get competitive bids. Just make sure the title and mortgage companies know which insurance company is the one you have decided to use when they prepare the final HUD and run their numbers and pay that first payment for you
Get some additional opinions on the roof condition and ask your insurance agent what the company policy is. Roof replacement is the greatest claim made to insurers, so they don't want to take on a new policy when the roof is already shot, but that's something that is usually addressed during the inspection period of a contract.