This has saved our butts probably 10 times with slippery tenants.In one very recent instance, a commercial tenant edited the lease to swap a Corporation out for his personal lessee status (AKA removing him as a guarantor), and literally added the Landlord's signature on it. 

Wanna swap houses?! 

I changed out the original 1970's boiler 2 years ago, I compared swapping to a propane high efficiency boiler vs an oil high efficiency boiler w/ indirect hot water heater.  

Yeah I can definitly agree with that, I ran into the same situation when I swapped Manyunk properties with Germantown in my model.

Or is it that both are being swapped under the LLC formed.

I bought the house in 2009, the a/c was a 1995 dated unit, inspection never noticed a lack of permit, the house was only permitted for central heat only, apparently in 1995 someone swapped out the central heat for a central a/c with heat.

I initially though I could just get a Home Depot special and swap it out.

Again, sounds like they foreclosed on duplex B, but sold you Duplex A.There is no reason for You to be signing a quit claim deed, unless you are swapping DuplexA (the You “bought”)  for Duplex B (the one they foreclosed on and you should have been buying).

In my experience, a great handyman can pain, do basic plumbing and electric, swap out toilets, replace drywall, etc.

Maybe eve a guy that carries used appliances for swapping out.