I would take out the 401K loan towards the downpayment.If you sell stock, you have to pay taxes - You mentioned the 15% federal capital gains tax rate(if you are not in the top bracket, otherwise its 20%).You may also be subject to the 3.8  Net Investment Income Tax. 

Federal law is there but the law that rules between state and federal is the more restrictive of the two..

But the 2 of 5 rule for excluding up to $500,000 in taxable gains might (we don't know how long you have owned it.)We also don't know your equity position in the property, or how much you are thinking to taking out of it.  

Interest is always taxable, no matter how small.

Do you realize that nearly a third of California's operating budget depends on federal funds?

Did the Cap-Ex on the triplex affect your taxable income?

It's neither quick nor easy, but it is life-changing and thus worth it.Flipping and wholesaling is NOT investing, it's a job and it is transactional and the profits (if any) are highly taxable income.

Would like to understand 1031 exchange rule to understand what is considered as boot that would be taxable. 

Does anyone know if the 90 day notice requirement is a California law or federal law? 

Their policy may or may not require a certified 3rd party appraisal for any taxable event such as a distribution in kind.Current valuation is all that matters here.