As someone who has coordinated 40+ deals in last 18 months for clients, I can tell you that the hardest piece of the puzzle is the property, the opportunity. 

Transferring mortgaged properties to an LLC may trigger due-on-sale clauses, but transferring to a trust first can mitigate this risk.

I tried QBO and Xero years ago and QBO would not allow automated transfer of data from AppFolio (my PMs software) to QBO; so, I have used Xero since then and been happy with it. 

I recommend you find a qualified intermediary who:Will not commingle your funds with other clients.Holds a Fidelity Bond with Errors and Omissions Insurance.Member of the Federation of Exchange Accommodators and Better Business Bureau.Wire Transfer Security measures to counter wire fraud.Have a great day!

Many investors start with personal ownership and transfer the property to an LLC later, but it depends on your long-term goals and risk tolerance.

So if I was dealing with a seller who was insisting on handling the transfer this way, I would be wondering what the seller is trying to hide... and I would figure it out.

@Chris Rendall couple comments,@Wayne Brooks is correct if it was a Homeowners policy now being transfer to an LLC and used as a rental. 

These risks include, but are not limited to, lack of liquidity, limited transferability, conflicts of interest and real estate fluctuations based upon a number of factors, which may include changes in interest rates, laws, operating expenses, insurance costs and tenant turnover.Investors should also understand all fees associated with a particular investment and how those fees could affect the overall performance of the investment.

Theoretically, at least.Since the U.S. courts routinely find these foreign asset protection trusts to be a sham, and transfers to these trusts fraudulent transfers, the assets in the trust themselves need to be beyond the reach of the U.S. courts system.

Your estate could still go through probate to determine how the LLC and other assets are distributed.You may be able to record a "transfer on death" deed for your property so it automatically transfers to another person when you die.