(Inspectors are generalists, so specialists are essential for plumbing and electrical issues in older homes.)Structural Concerns: If potential structural damage is spotted, hire an engineer to assess it properly.Be Diligent and Proactive: Old homes often require extra due diligence.

Quote from @Max Wilhite: Welcome to the BiggerPockets community in the tab at the top of your screen it says starting out under that you’ll find a search engine where you can find all listed real estate meet ups in your area.Thank you! 

Two options- pay the Architect to make revisions or hire a Plumbing Engineer to create plumbing drawings.

I have not seen any "main stream" versions of this just back country engineering but it's a solid concept and works well. 

3.b. - COE Core Of Engineers..

Your engineering and project management background must be a huge asset in analyzing deals and market trends — perfect for the dynamic Bay Area market.

It includes everything you have asked for.I could also connect it to other booking engines like Booking.com and TripAdvisor, but have not set them up.Customer service is wonderful, and they are always super-responsive with any requests I have.The only gripe I have with it would be their website templates, should you want to build your direct-booking site directly through them.

And clients won’t miss the current system.I think you're engine is fueled on 98% assumption and 2% fact in this regard. 

Steps 2 & 3 would be the main contributions of a Civil Engineer who is involved. 

I have some web design skills (I'm an engineer, so easy to learn new programming languages) and I'm currently testing my new system to manage the tenants.