Family members are allowed tax-free gifts and that can come in many forms, just talk with your CPA and you will should be able to structure it without any tax burden.

Secondly, short-term rentals provide flexibility for owners, allowing them to potentially use the property themselves when not rented out.

The flippers who COULD handle the volume that a flipping fund would allow them to take on, don't need a fund, because often times, anyone flipping at that volume is already making close to 7 figures a year, and wouldn't want to keep splitting it.Alternatively, I, personally, would not invest with a flipper that hasn't done it, a lot.   

As mentioned above, they specifically allow this.  

I'm just here to note that an LLC does not offer a single tax benefit, nor does it allow any deductions that aren't allowed without an LLC. 

.- Many of these HCOL areas also have strict limitations on AirBnB or short-term rentals... that do not apply to owner-occupants - thus allowing for extreme cashflow potential for house-hackers.

Obviously if I intend to have a top performing STR in this market, my buy box will allow for a much higher max purchase price, but I wouldn't feel comfortable with shooting for the max if there aren't clear ways to beat these competing properties.

Pooling the funds together allows me to maximize every investor dollar and minimize idle cash.

Many lenders won't allow actual cash value or ACV.Repair cost or replacement cost?  

An LLC shields personal assets from business liabilities, while S-Corp taxation allows you to reduce self-employment taxes by taking a reasonable salary and distributing remaining profits as distributions, which aren’t subject to payroll taxes.