Your first trip should be to the Planning Dept and ask if it's possible based on the zoning, and if they would view it favorably.

Start with BiggerPockets Ultimate Beginners Guide (free).

They let my on-site manager know they were going to "take a trip for a birthday party" and have not returned. 

We even made little signs to go up on the. door and on the kitchen to warn about fraud since it is more likely with self-guided showings.

Consulting with a zoning attorney is advisable to assess the feasibility of your project and guide you through the necessary procedures.Hope this helps!

Do they actually deliver on what they promise as far as providing their members deals, and guiding them through the buying and rehab process?

While the IRS does not mandate a physical site visit, the IRS cost segregation audit technique guide (ATG) does suggest conducting “field inspections.”It’s important to note that the ATG is not an official IRS document.It serves as a guide and cannot be used, cited, or relied upon as an authoritative source.However, the recommendations in the ATG are worth considering.According to the guide: “A field inspection is recommended to document the physical details of the building, type of construction, materials used for construction, the assets contained in the building, the size and types of building systems, and any land improvements that were included in the purchase of the property and the condition of that property at the time of purchase.”So while the IRS does not require a site visit for cost segregation studies, following the guidance from the cost segregation audit technique guide can be beneficial.

Our next trip is tentatively planned around the holidays. 

Start by reading the Ultimate Real Estate Investing Guide: https://www.biggerpockets.com/guides/ultimate-real-estate-investing-guide/introduction2.

But even with that, he needs someone to guide him or JV with him who isn't going to take advantage of his youth and inexperience.