It’s my understanding that my potentially taxable gain would be $230k in this case ($500k minus $200k + 50k renovation + 20k costs to sell).

Taxable value > $1M.

Buyer with higher Down Payment most likely will be selected as it gives a sense of more bonafide and less risk to the seller.Weight the tax deduction of interest payment between primary home vs rental investment, please check with your CPA.The interest on your primary home together with property tax and other personal allowable deduction as long as above standard deduction can reduce your taxable income. 

Fire/hazard insurance for a LLC vesting is more expensive than held in a Living Trust or your names.I'm certainly not a tax expert but in my opinion since a single member LLC is considered a disregarded entity for Federal tax reporting purposes, I also believe the conveyance to the same LLC would not be considered a taxable event. 

So if you spend all of the money you'll avoid any taxable boot.Any money you have left over after your purchases will be taxable boot.

Obviously, if the taxable gain is nominal or you have loss carry forwards, skip the 1031.

In that event you'd just as well  balance the mortgage with cash to take 140 or so cash boot to pay the tax you'll incur and have a little something to play with because putting all the cash will still result in a taxable event if you purchase less than what you sell.Nice problem to have. 

As for the annual tax, yes you need to pay tax every year, but you should be able to bypass the first year now: "The new rules established by the state’s 2020 Budget Act (AB 85) exempt any LLC that organizes, registers, or files with the California Secretary of State on or after January 1, 2021 and before January 1, 2024, from paying the $800 minimum tax in their first taxable year."

Having more debt that has positive cash flow is good debt and usually not taxable.  

So, although the money from the initial cash-out refi isn't taxable (because it's a loan and not income), you also don't get to claim some sort of tax exemption when you pay it back or exclude it from the overall capital gains.