Good turnkey companies do this hundreds of times a year, (should) have in-house contractors that do the rehabs, have streamlined processes that result in consistent quality products and lower overheads per door (if you rehab a lot, you pay wholesale prices for things like toilets and flooring and HVACs), so it's easier for us to make money through forced appreciation because of economies of scale.So, if you want to put the work in and take on the risk, you could end up with a higher return doing something like a BRRRR at a distance - where basically you do what a turnkey company does, but then keep the house as a rental or sell it.

The First: Is a newly remodeled duplex walking distance from the college campus.

We are husband/wife team doing repair, remodel, and renovate for others while obtaining homes to do the same and to flip to first-time home buyers or start-overs. 

This makes me think that I should learn the necessary skills of remodeling and do it myself to cut my expenses way down and thereforeincrease my total ROI.

On top of that both units are on a single electrical entrance and despite some of the waste lines being ABS, the toilets were all 5-gallon models from the 60s, there is one original claw-foot tub and a 1960s shower unit with a 2.5+gpm fixture.  

We got a full remodel, rents were paid the whole time and during the process we actually made some changes like adding over head lighting and outlets.

Also, it is often tiered with lower rates per thousand gallons for relatively low usage, but can escalate dramatically for high usage (heavy lawn/landscape watering, pool refills, leaky toilets, etc.),  Sewage is usually a multiplier of the water usage.  

HOA fees are high: Point Dume Clue HOA fees from what I can find online range from $1K-$3 per month, but I can’t seem to find a number to call to talk to someone specifically and this worries me.Building/Remodeling in the Club: How easy is it to remodel and or build in the Point Dume Club / Malibu?

Remodel:  Buying a fixer upper sucks as a rental because while the property is being rehabbed, it is essentially sitting empty doing nothing but creating bills for you. 

But your overall estimate of about 50k for a full remodel on a house that size seems like it would  be in the ballpark though.