Cars are covered by car insurance, not homeowner or renter policies.Tenants files a claim with their car insurance, and you don't do anything.

There are two separate issues here: one is combining your personal and business banking which can complicate filing your taxes and is generally frowned upon.

In my view it more useful to focus on the total asset value rather than the number of properties in the LLC.I have found that filing the 1065 for a partnership LLC is simpler when the total asset value is less than 1 million.

You are moving into a very gray area if you are borrowing money from more than 1 family member and it's not for a specific deal as you should need to file an exemption from the SEC.

This can be fairly straightforward, depending on your agreement and if a partnership return was ever filed, you'll want to report half or your portion of the basis in the property as well as half the sale price minus expenses.

As it is, I've gone back to just keeping paper receipts in a file folder and electronic receipts in a gmail folder.

You are simply just going to be paying your accountant to file 3 tax files for 1 property. 

I then hired an architect (or at least I thought it was an architect) to use the CAD file from the surveyor to draw the proposed addition to the house by using the surveyor's site plan.

You are subject to failure to file and failure to pay penalties.

They also seem to be keeping up with the LLC state filings every year (I check the secretary of state website from time to time).