There may be a way to mediate your risk and recover your testing costs and remediation expenses. 

For that kind of investment I just wouldn't risk it.

As you add more and bigger properties, you'll at some point likely transition to professional management, which will add more risk. 

My concerns are the risk of default and how hard it is to take back the mobile home. 

Should I install bigger, updated tiles for the shower and risk the mold mildew grout issue or just install a prefab, fiberglass shower stall? 

Lots of people have the discussion about tax and legal implications, which there are many and should be discussed with an accountant and attorney, but you'd want the LLC if you want to buy properties directly in the name of the business without having to do quit claim deeds and run the risk of having the loan called due.

While I believe the laws are federal, and therefore the same everywhere, a local professional with extensive experience in the area will be able to tell you based on the type, age and location of the property what your potential risk would be and the minimums required by law to have it taken care of, if necessary.

If I were you, I would risk that she won’t go to small claim court for the small amount of $210, and ignore her.

I personally have a HELOC on my own home, which I use for flipping.But there are two big risks with HELOCs. 

Yes, there are some great buys in that area, but to me, the risk/reward ratio is too high.Start driving south from Joppa Rd on Harford Rd and to me, the whole tenor of the neighborhoods change at around Moravia Rd. and certainly by the time you get to Argonne Dr.