Hey there!
Congrats on getting the offer accepted, and it's awesome you're thinking ahead about structuring the ownership in an LLC. You've got the right idea when it comes to liability protection and separating the income for tax purposes, but there are a few things to consider with the "due on sale" clause.
When it comes to paying the down payment, it's perfectly fine to use your personal account to cover it since you're personally guaranteeing the loan anyway. After closing, you can transfer the deed to the LLC, but the key is timing. Lenders sometimes don't mind if you transfer it to an LLC after a few months, especially if you're still making the payments personally. But be cautious, you could check with your lender directly to avoid triggering any concerns.
As for waiting a few months before transferring the deed, it's often recommended just to avoid drawing any immediate attention to the transfer, but every lender is different. If you move forward, make sure the LLC is properly set up and operating as a business—especially when it comes to collecting rent and paying the mortgage.
Lastly, about taxes—transferring ownership won't necessarily keep the income off your personal return if you're a single-member LLC, as it's considered a disregarded entity. But it could still provide better organization and protection. Working with a CPA on your tax strategy will definitely help ensure you're getting the benefits you're after.
Good luck with the closing! Feel free to reach out if you need anything else.