But from a practical standpoint, even 8 adults would exceed fridge capacity, create bathroom bottlenecks, parking problems and put extra wear on the property.

I'm a newbie to real estate investing, so little words are very much appreciated :)Big picture if it helps: I'm exploring an all in one so I can plop extra savings into it until I'm ready to purchase additional properties and then can pull the money from the all in one for a downpayment elsewhere and then will continue to throw money into the all in one from my main job as I save for additional downpayments.

The "less" option would be to "just" fix things at around $20-30k then down the road spend about the same when its time to sell the house to make it look the best and not get the extra value that a bigger project would bring and not enjoy a nicer, fixed house until then

We project we would still be cash flow positive even with the extra costs of the HELOC, but we would ideally rather have more cash flow then less at this timeWhat are things we need to be considering or thinking about?

-I would need to hire a Real Estate Attorney to draft this unusual purchase contract, and that would be an extra cost.

If you got the extra cash to repair HVAC I would invest in that, if you are on a tight budget maybe ask someone to lend you some money. 

Cost to acquire is ~100k and I plan on spending an extra 15k on repairs. 

Should I replace tiles with the luxury vinyl to look nicer (extra $1k to remove the tiles for such a small area, and vinyl would not be durable) or leave the tiles?

@John K. the more you immerse yourself, the more you will learn and get ahead.So, buy a 2-4 unit somewhere and rent the other units out.You can even rent out extra bedrooms in your unit to maximize cashflow. 

Do you have extra land you can divide and pay down debt?