I am hoping to roll these two into one loan and reduce my monthly payment/ interest rate on the HELOC as I will be having the debt long term.I also currently own a 11 spot RV Park which I own all 11 units and is currently generating $10,375/month in rent.

@Eugene Lubman Selling the property to your parents allows them to generate passive income while enabling you to perform a 1031 exchange to defer capital gains taxes.

Before listing it, I had lots of expenses, including painting, floor refinishing, plumbing repairs, staging, cleaning, etc.In a 1031 exchange, I purchased two small multifamily homes which also have some roof work, painting, plumbing, etc. 

I am not sure about what you are reflecting in the cleaning number but for me 1) it is shocking what cleaners charge but it is not where you want to try to save money for quality 2) it is a pass through, the guest pays it. $250 per turn would be for larger unit and very good job.  

But hold on to all communications with them regarding this beause if this goes ballistic, THEY have a great deal of liability in this.2) As @Nathan Gesner said, get a new Mold Remediation Company and have them go over the entire house 100% and re-treat it, then give you a written certification that it is safe and clean.3) Get rid of your brother too.

The problem is the HOA doesn't allow VRBO rentals, only year long leases so I wasn't able to generate cash with this property.

Guest checks out, cleaners arrive to clean, conduct post stay inspection, and reset the home for next guest.

While an SDIRA will have UBIT on leveraged real estate, a solo 401k is exempt from UDFI (unrelated debt finance income) generated UBIT.

There are a ton of illegal basement apartments all around Hudson County--maybe 10-15 years ago there was a program (at least in Union City) where many of these apartments were made legal, I think partly as a way for the city to generate revenue, and partly as a way for the city to have some oversight, since people were renting these apartments out regardless of their legality. 

Then you also have it for the cleaners as needed.Then I would schedule some time for you to head over and do a full deep clean on the carpets yearly if they don't get messed up in between.