They have some things designed for higher end investors.

Better materials such as stronger  lumber were used when the earlier vintage properties were built and many  contained design characteristics such as stone or brick work and intricate millwork that are too costly to replicate today meaning many buildings are significantly below todays replacement cost. 

I am aware of California's Prop 13+58+19 prop tax inheritance evolution and its complexities with LLCs but we are not considering inheritance or parent->child gifting etc.

Ironically, platforms designed for real estate (Zillow, Apartments.com, Rentler, etc.) produce very few tenants for me, compared to FB Marketplace (and I also find a lot of their functionality to be user un-friendly, from the landlord side). ...you'd think that platforms custom-made for real estate would make the process a snap for landlords, but it takes me a lot longer to post and manage rental listings on Zillow or Rentler than it did on Craigslist.

For example if you wanted to gift $100k to your child to purchase a business, it may be best to make your child manager, with say a 20% interest, while you and or your spouse maintain a 80% interest.  100% of any net income can still be received by your child as manger, or even for just his 20% interest, as profit allocation  need not align with ownership percentage in an LLC.

Seems like an overkill and all you need is an insurance policy as any good attorneys first question will be "how much did the LLC who is to be separate from you pay for the property" - when the answer is zero and it was gifted. the next question will be do you gift properties to others as well?

Following this, I consider it another pro of our situation that I have the ability to do significant property renovations myself, and between my wife and I, we make a pretty good design team.

BiggerPockets is full of resources designed to help you along your journey, whether you are just getting started or a seasoned investor.

., how much design work does the civil engineer need to do. 

Congrats - love the design