That is an acquisition cost that will vary depending on the buyers circumstances and thier finance situation. 

I can't imagine the stress/anxiety of positioning myself in such a way where I am reliant on a W2 income to buoy n > 1 properties, keeping them afloat month after month despite receiving a W2 income, hoping and praying life circumstances don't force a liquidation, especially in a rapidly changing market where appreciation is not a guarantee as supply continues to pile up and major metro STR markets continue to find equilibrium.

And after unforeseen capex, we usually net $437 a year.

This is a rather narrow set of circumstances, but it is out there.For your situation, sounds like you would just be considering items 2 and 3 for tax purposes. 

Ultimately, separate renter's insurance provides better protection, minimizing confusion and ensuring proper coverage for unforeseen circumstances, benefiting both landlords and tenants.

If I will apply now for HELOC does it affect my credit score for my next primary application) The builder just pulled again my credit last 5/21/24 (for the second time), Does it affect in any circumstances my loan will fell out with the builder?

The decision depends on your personal circumstances, preferences, and resources.

They would be realized depending on favorable circumstances.

Both FNMA and FHLMC permit this, under the following circumstances: Notes: For all such transfers affecting mortgage loans purchased or securitized by Fannie Mae on or after June 1, 2016, the transferee is not required to occupy the propertya limited liability company (LLC), provided thatthe mortgage loan was purchased or securitized by Fannie Mae on or after June 1, 2016, andthe LLC is controlled by the original borrower or the original borrower owns a majority interest in the LLC, and if the transfer results in a permitted change of occupancy type to an investment property, such change does not violate the security instrument (for example, the 12 month occupancy requirement for a principal residence).The servicer must notify the borrower that a property transferred to an LLC must be transferred back to a natural person prior to any subsequent refinance application in order to meet Fannie Mae’s Selling Guide underwriting requirements.Citation: D1-4.1-02: Allowable Exemptions Due to the Type of Transfer (04/13/2022)Now, you will still have the Note and reporting in your name individually and will still be personally responsible for the mortgage and most likely, the manner of transfer will enable any litigant to pierce the veil of your LLC, but you'll have what you wanted, for whatever reason. 

My question is- what if life circumstances change and I need to sell the owner occupied portion within that 3 year window?