If I have some cash do you recommend clearing the loan or invest instead for next property with proper planning ? 

Quote from @Matthew Irish-Jones: Quote from @Mark Cruse: Yes, there will be more expenses above what's mentioned here but if this is done properly it can be kept to a minimum.

Still up to me to properly utilize it and get the deals contracted.

A lot of the popular areas in Charleston proper that are not licensed under the old laws now require the owner to live on the premises to obtain an STR license.

I think smaller markets say sub 50k population would have a larger impact from one big move from a manufacturing facility or something like a Amazon processing center.

Crossing the lines may not provide proper liability protection.Personally, I just kept my SF rentals in my name and got excellent insurance coverage, $500K per property plus a $2M umbrella.

Yes it's a huge problem.You should fix this correctly now.Open the walls and put in proper sound reducing insulation.

The ownership structure as indicated on the title must match the named insured on the policy to ensure proper coverage.

Have to look at these things properly.

Without proper support, removing the wall could have compromised the structure of the entire house.