For example, the house is listed for $500k and it has $300k in mortgage left at 3%Could I offer $500k and "assume" the mortgage of the seller?

Title insurance should also catch this.

They suddenly lost my insurance information and now said couldn't collect my monthly mortgage. 

Would it be a good idea to file the claim with the new insurance company for the roof? 

Yes, housing is cheaper but we found groceries were about the same, eating out was roughly the same (although we don't do it too often anyway), car insurance was higher, home insurance was about the same if not higher in MI, and property taxes on my $460k Michigan home were the same as I now pay on my $740k CA home.Overall, if you can make this work I like the idea of it.

Most lenders will offer up to 75% of the new ARV.

I saw an ad for EverSeal offering a 50-year warranty for their flat roof system.

The only change to the existing law was to expand the definition of "Provide real estate brokerage services" to include the following:Regardless of whether the activity is engaged in for another person, engaging in the buyer or selling, offering to buy or sell, or marketing of real estate or otherwise dealing in contracts, including assignable contracts, for real estate or options on real estate, on two or more occasions in any 12-month period.Principals buying and selling on their own account clearly fall within this expanded definition.

Now I got a notification my insurance won't be renewed.

What is the best cash offer  i can bring to the table since the owner want his equity and does not want to loose the home either.