Their asset would constantly be maintained and rented. 

This is automatically done by a control valve.Post your water analysis with the current iron concentration, pH, hardness..etc, and we can discuss what you need.

I'm new to property ownership, so I'm not really sure about much as far as property maintaining.

how do you maintain control of the sale?

Plus if you think about it if the property is maintained the price is likely not gonna go down and so you should take into account equity gained.

Does it cost a lot more to maintain a 2,500sf house in Palo Alto renting for $10k/month compared to a 2,500sf house in Elk Grove renting for $1,800/month?

I would concentrate on one strategy at a time.  

No need to hire a chimney sweep every six months, provide & maintain fire extinguishers, extra CO alarms, this list goes on.On this one, I would be aggressively defensive. 

Meticulously maintained, all brick, historic home on coveted street a few minute walk from OSU campus. 5-6 bedrooms, only one bath and not so easy to turn into duplex.

Building a quality trustworthy team is not always simple and it takes work to maintain the team (even local takes work to maintain a quality team).As for buying your primary residence I have two considerations: 1) how long do you plan to live in the area 2) how are the long term appreciation outlook (in LA the long-term appreciation outlook historically has been excellent).