Do you use an individual off craigslist, etc or do you use a company?

Those "schedules" are for military contracting or official military purchases, not for individual use. 

Seeing as how I assume you would never have the major expense of replacing a roof or maybe even an HVAC system as some high rises may not have individual HVAC units for each apartment it seems you could allot less to this.

Following are the similarities and differences between the solo 401k and the self-directed IRA.The Self-Directed IRA and Solo 401k SimilaritiesBoth were created by congress for individuals to save for retirement;Both may be invested in alternative investments such as real estate, precious metals tax liens, promissory notes, private company shares, and stocks and mutual funds, to name a few;Both allow for Roth contributions;Both are subject to prohibited transaction rules;Both are subject to federal taxes at time of distribution;Both allow for checkbook control for placing alternative investments;Both may be invested in annuities;Both are protected from creditors;Both allow for nondeductible contributions;Both are prohibited from investing in assets listed under I.R.C. 408(m); andNeither may be invested in your own business. 

For example, I was very recently involved in a portfolio purchase (didn't go through) where the overall numbers looked good but some individual properties in the portfolio were not up to par, and I didn't notice until a little longer than I should have.

Subscribe to multiple wholesalers lists to get a solid feel for areas and for individual wholesalers figures. 

The NAA average for individually metered properties is $4,800.

I want all of the work done by licensed individuals.

In this process I've came across many individuals who own multiple properties with each under its own LLC.

Also, I don't know that you can have a registered DBA for an individual's name.