Generally speaking, with SFR or small multis, I just rely on the lease/rent roll (and some form of proof of payment; i.e. bank statements, deposit receipts, tax returns, etc.). 

If not, what are property tax sales? 

Dig deep into tax strategy, tax efficiency, etc  Learn about estate planning. 

Who covers the tax bill when they don't pay the tax bill or the insurance? 

Hi Ricky,Being in operation for 10 years with mid seven figures of assets and NNN leases,it would be wise to speak with your tax advisor regarding if the tax set up should be an LLC, an S-Corp  or a C-Corp.It would also be wise to speak with an asset protection attorney to find out if this is something that might be beneficial to you in that area.

.🔹 Property Tax Relief – If your property is severely damaged, you may qualify for reassessment and potential tax refunds.

I've been knocking on doors, there is one that seems like it's abandoned, however despite finding the owners name from tax records I cannot seem to get in contract with them to make an offer (despite trying x, y and z). 

And it can work really well for you as long as you pay attention to the statute requirements.In order to defer all tax you are selling investment real estate and buying investment real estate of at least the same value you sold. 

Are there any fees/taxes associated with AL licenses?

I've been using the GE  GFW148SSMWW // GFT14ESSMWW models which comes to $1,650+ tax for units and stacking kit.