The owners refused my advice to reduce price and they both sat vacant for months.

I have spreadsheets filled with material lists for every phase of the build that includes pricing for materials as well as labor, and sources that I use for them.

Are you able to reduce your expenses quickly and easily if needed?

Selling at FMV avoids the gift tax but provides your child with a higher tax basis, reducing their future capital gains liability.A better strategy for selling below FMV is to sell the house at FMV on an installment note, then forgive interest and principal annually up to the gift tax exclusion amount.

Limited labor and resources : Unlike the catastrophic fires in Lahaina Hawaii there are significant resources in Los Angeles to contribute to recover, but quality contractors, tradesman, plumbers, electricians and laborers have long been in short supply.

True, converting a personal Schedule E to a partnership will indeed reduce your IRS audit chances, statistically speaking.

Could seller finance (not recommended) to reduce initial burden and spread it out over time

If you don't understand the basic principles of construction, market standards (i.e. average cost per labor hour, cost per sqft for flooring, cost per sqft for hang/finish drywall) then you may find yourself getting taken advantage of without even knowing it.

2.Are there strategies to reduce the required down payment or secure better mortgage terms?

I am not an accountant or tax professional so I would recommend talking to your account about what that means and maybe some strategies on how to reduce your tax liability