(for both the sales floor and for employee areas, for purposes of loss prevention)  Does "smile, you're on camera" really mean "please sue me as I am exposing myself to liability" in the state of NJ?

Financial screening will prevent problems - even with kids

If they prevent you from making 1 big mistake, the few thousand bucks you pay them would be well worth it.Probably a good idea to pick up the BiggerPockets Rental Property Investing book.

Are there any laws preventing me from using that money to purchase a rental?

It is to prevent the buy and hold investor you see so much of in baltimore. 

I understand the logic behind why people just deduct them as overhead, but technical rules prevent doing so.

This is the reason why LMR is collected to prevent tenants from stiffing a landlord at the last minute.If you can find a replacement tenant for the first of September you can refund her LMR otherwise she is responsible for September rent.

Hopefully you are addressing issue preventatively so you wont really have to use the HELOC while you're low on cash, but it is there for security if you do.

I have actually been on the seller side of this situation, and it is very frustrating when a tenant prevents a showing to a potential buyer.

An ounce of prevention, right?