I've networked with an experienced flipper who found the deal and proposes I finance the job, he does most of the work and manages the subs and I take up the painting of the house and lend a hand with some labor. 50/50 split on the exit.  

So if you are going to pay the same dollar amount for property taxes in December versus January, then might as well get a deduction at a higher tax rate.Perhaps you are seeing less luxury rental sales because they tend to be second homes rather than rentals....Also that bit about higher chance of audit... are you maybe thinking about the SALT work-arounds that NY and other states like CA and CT are proposing?

He's partnered with multiple investors on other projects, and has proposed that I go in with on a smaller flip so that I can have some experience going through the process and we can both make a little money.I have about 50k liquid in my savings right now, and hes proposed that I put down 5-10% percent to go in with him on an upcoming flip.

The first thing I would do is ask the tenant what she proposes.

Ken, you will run afoul of the IRA rules with this proposal.

“We’re capturing revenue where it is,” Kaplan said, “and we’re capturing the revenue that has a relationship to the problem of homelessness.”https://www.mercurynews.com/2018/07/17/proposed-landlord-tax-would-raise-money-to-house-oaklands-homeless/

Also screen who they propose as you normally would. 

That's one reason I appreciate Fortune Builders - most of their students approach this like a job, and when they send you a proposal, it's DETAILED! 

IF you are not experienced with this, you may be better off retaining an architect on an hourly basis to help narrow and document the current conditions and proposed changes.  

The text of the proposed House Bill regarding accredited investors is: "any natural person the Commission determines, by regulation, to have demonstrable education or job experience to qualify such person as having professional knowledge of a subject related to a particular investment, and whose education or job experience is verified by the Financial Industry Regulatory Authority or an equivalent self-regulatory organization (as defined in section 3(a)(26) of the Securities Exchange Act of 1934)"The last part is of most use, but whats an equivalent self-regulatory agency?