You must document,documents all damages and by all means let the son know since he is responsible mothers actions.

In the duplex basement is a working washer and dryer and it sounds like you never had a discussion about it one way or another, and whatever documentation you have doesn't explicitly mention it.Isn't it perfectly reasonable for her to think that a basement washer/dryer is included in the overall rent and there for the use of both units?

I also tell my applicants that I do everything based on what the documents say.  

A Solo 401k provider will be able to prepare IRS-approved documents for your business that will allow you to participate in the plan and get all the features these plans offer. 

In the end, everyone ends up with a bunch of pdf documents, with a random mix of some signatures digitally pressed in the pdfs, some signed & scanned, some signed & faxed.

Usually, you'll have to obtain the documents associated with the park (i.e. rent rolls, leases, tax returns, etc) to make a better determination.

All written, documented, available for managers to act on.

You can rate and term refinance out of a mortgage, but not an installment sale or similar, depending on how the language on the relevant document reads. 

In Southern California a 7% loan isn't uncommon, but other places the lowest you could get is 15%.As for being a private lender, you could work off of JVs or partnership agreements or that kind of thing, but the cost to do a real hard money loan on your own where there is a lien recorded and get a lawyer to work up all the documents and everything would be cost prohibitive for a few loans.... that's what I meant

I would always have an attorney review documents regardless.