I'm with @Jim K. on this one. 

At that point I’ll either get a PM in place, or I won’t mind incurring the sales transaction costs, and either set returns of NNN, or the vagaries of DST’s fees and reliance on their management team not to f**k up the project returns ;)So how has your experience been with property management (PMs)?

I have the opportunity to start investing in my 401(k) through my employer.

Deficiency judgement or not.

Whether it be schedule C, E, K-1 or whatever.

If your investments will be more interactive or time-sensitive, you will want to evaluate providers of Checkbook IRA LLC programs.2) I would strongly recommend against using any 3rd party administrator or IRA custodian for establishment of a Solo 401(k). 

Knowing that you can actually make an additional $11,500 on the deal, could someone use their self directed 401 K to lend their LLC the money?

An FHA 203(k) loan rolls renovation costs into an FHA loan.

@Steve Babiak or @Chris K. may be able to give you some advice on that.

Where to find those investorsAny non prohibited person can set up a self-directed IRA or 401(k) to invest in your LLC.