@Michael BlackwoodIf one qualifies by being self-employed with no full time employees, then the Solo 401(k) is likely going to provide some advantages over an IRA as a 401k is simply a more robust retirement plan with features such as higher contributions, a personal loan provision, ability to hold both tax-deferred and Roth funds, and an exemption from a small tax on leveraged income in real estate.Whether you A) qualify and B) will benefit from those differences is a matter that hinges on the details of your situation and investment goals. 

Best bet is to sub each piece and manage the project yourself.

I get calls to my piano business sometimes for that and I bet I could fill it up with some marketing.

Your best bet is to start marketing to off market properties because you will have multiple roadblocks trying to wholesale a property from the MLS, unless you plan on buying it yourself and then marketing it to buyers.

A safer bet is is 350 though.

Don’t bet on speculation or appreciation to make a deal work.

I bet not very common.

Your best bet is to contact the Utah Assocation of Certified Public Accountants (UACPA).

I bet they do.

Also, not sure how familiar you are with Harrisburg and what your management experience is, but if you're purchasing 5 unit mixed use buildings in Harrisburg for 100k I'm willing to bet the area is a bit 'rougher' and could be a management intensive property that may not be the best deal for a 1st time investor.Best of luck in your journey and don't hesitate to reach out to me if you have any questions.