Here are some indicators to help you assess a buyer's seriousness:Questions: Serious buyers will ask detailed questions about the property, such as maintenance costs, neighborhood amenities, and property taxesStrong Offer: If a buyer makes a strong offer quickly, it often indicates a high level of interest and intent to purchasePrivate Buyers: If approached by a private buyer, ensure they provide a Letter of Intent (LOI) and proof of funds.  

I recently backed out of a deal out in Harrisburg due to being in flood zone, I was informed by my realtor that it costs $1800/yr flood insurance policy alone.

A few other methods cost some money but is usually just throwing away small amounts at a time. 

These platforms typically have billing policies where you pay a per unit fee per month to the software and you get regular updates and support each month.There are a number of low-cost platforms available that are able to offer you a lower price by passing along some of the costs to your tenants (payment processing fees, applications, tenant screening, etc).

A good real estate accountant can save you thousands of dollars by leveraging entity selection and formation, tax deductions, cost segregations, bonus depreciation and tax planning.I recommend finding an accountant who specializes in real estate taxation, business taxation, financial planning and tax planning.You may want to consider working with your accountant remotely to expand your options.I would also recommend looking for a accountant willing to work with you throughout the year.

(It’s multi-family but not entirely stabilized.)Rehab Costs: How much should I budget for bringing vacant units to market-ready condition?

I will say, short term rentals require a bit more work, and if you are moving out of state, you may want to take a look into getting a property manager ( take that cost into account when running the numbers ).I hope that helps, reach out if you have any more questions. 

Determining the cost on something like this is only something you'll be able to find out by talking to the city.

You have any idea how much money it would cost you to attempt to initiate a class action?  

Not sure the cost of this for you but I feel with hot tub and fireplace you already have a lot of warming options and not get much additional revenue.