When I ask about cash to start investing, I literally have the cash, and am curious how much capital you think I should allocate to this endeavor.

Make sure you allocate time to yourself daily as a non negotiable-- Wait until it's right time to bring a partner on.

We now have statewide rent control so I'm not sure how this impacts my ability to charge back their full allocation of utilities.

Set a budget as soon as you receive your income and allocate the funds directly to your investments.

Yes but only the portion allocated to actual real estate counts for the 1031.5.

the amount allocated to your primary residence would be $200K (25%) and and investment portion would be valued at $600K (75%).  

However a single member LLC may not protect the owner from creditors.For tax purposes an LLC can file as an S Corp (file S election w/IRS first)No upper limits on the number of LLC members, S Corps up to 100No restrictions on LLC ownership interests (flexible), an S Corp can have only 1 class of stock but can have differences in voting rightsSpecial allocations in income, gain, or loss in an LLC is permitted but not in an S Corp they allow pro rata allocations because of the stockIn regards to distribution and contribution of property (not cash) an LLC may have tax advantages over the S Corp.

@Jess Sanchez, as others have mentioned, a viable option is to sell your current home to allocate capital toward the purchase of a house hack to get you started.

@Joel Jennings, congrats on your first deal.It depends on how much equity you currently have, the interest rate you had for your current duplex, and what is your current debt to income.For the first 7 years, a big chunk of your monthly mortgage payment is allocated to interest.

I like helocs on primary residence because it is designed for short term use and the payment gets allocated to a project that will make money in 6 - 12 months. imagine if they did a deal with you, and after 12 months or so you refi or sell that deal and the family member gets their 600k back.