Enter the home to an Open concept with beautiful wood beam 10 ft vaulted ceilings.

Bathrooms, toilet rooms, and laundry rooms shall have a ceiling height of not less than 6'-8" above the finished floor"Additionally, in th following paragraph 1207.2.1; it also notes an exception for similar residential conditions which allows "Furred Ceilings" (Ductwork, Structural Beams, etc) to be permitted as low as 6'-4".In Short; the Diagram you posted indicates the correct conditions that would apply to your residential basement. 

We've replaced 5 water heaters in a single year, had plumbing stoppages that resulted in 3-5k worth of work, and even had to replace 1/3 of the pier and beam foundation in the house we're currently living in.

The properties are free-standing, steel beam construction and about 20 years old.

New carpets, paint, interior French drain with warranty, new structural support beam in basement, 2 new full baths, and much more.

Even if you don't buildout all of the floors on a vertical, you still have to put in stronger footings and beams.5. 

There’s also these weird support beams that I’m assuming the current owner installed.

Get floodlights installed on the property beaming out front.

Mainly, because structural issues can be a complete black hole of money, time, effort--and it can be very difficult (and costly) to anticipate just how much money, time, and effort they'll consume.First, you'll need to figure out what's causing the structural issues--it could be settlement at the footers caused by ground water, it could be wood rot or termites in a beam, it could be masonry degradation caused by water coming off the roof, it could be improper drainage of the roof, it could be tree roots degrading the foundation, it could be a plumber who cut out a critical joist to install a line 20 years ago, it could be improper construction, it could be any or all of those things, and it could be any number of other potential causes.

Good point on the importance of getting laser focused on the right market.There is a lot of incorrect information out there when it comes to price declines.