If they disagree, they are free to look for someone else to list instead.

Please feel free to pass out any knowledge/tips for someone very green.

@Stephen FrazierI'm not 100% sure what you're asking, but I would strongly recommend against buying something with 100% financing where part of that financing is a HELOCYou will probably just lose moneyIf the home is owned free and clear, maybe the kids would do seller financing? 

If it’s feasible, how long might the process take, and what costs could I expect for the necessary permits?

The question is what is the expected cost both in hard expenses and also opportunity cost.

The purchase of the unit is going to be sooner a few months, you could wait to rehab both at the same time which could potentially help reduce the costs of the rehab. 

not a terrible idea, but the money can be put to much better use), 3) short-term rental, which is also part of what I proposed and which weirdly you argued against when I proposed it.

Just keep in mind that construction costs can add up and timelines for building can vary.

Here's a fundamental explanation to get your juices flowing:Assume a house costs $200,000 and rents for $1,500.

See the 2020 aerial view below.Very little undeveloped private land is left in the Las Vegas Valley, and desirable areas cost more than $1 million per acre.