FHA does not allow you to do things outside of the home like adding a fence, hard scaping, retaining walls...   

It is great that you are thinking of adding to your portfolio.  

It offers flexibility as a landlord to be able to offer more or less rooms as needed, protection to the landlord in that you can hedge with adding LTR or STR to the mix, and simplification to the business as your only dealing with one address.

You are only adding complications and costs with the LLC with no upside  This is all assuming there’s been almost zero appreciation and you shouldn’t sell tax free while you have the chance. 

Consider starting small by house hacking a single-family home, renting out rooms, or adding an ADU if possible.

When you initially buy a property, ad 20% DP, you are buying a property that's worth 5 times what you are paying for it. 

Quote from @Eduardo Perez-Borroto: Since the HELOC was not used on improving the home you cannot deduct the interest, nor use that to offset your capital gain.Would adding a battery bank system to my solar panels count as home improvement? 

Following Sean’s instruction, I signed up for Google Ads.

Adding a washer/dryer to a $500,000 two-flat in Rogers Park could allow you to raise rents by $150/month, significantly boosting your ROI.8.

If it concerns you that much, adjust the purchase price to take into account this added risk.