If you're going to invest in any heavily populated area, pay for a consultation on landlord-tenant regulations if you're looking to keep and rent. 

It's the above complexity times 10. if you treat the entire building as one item, you have to spread everything over a long period of time, and nothing can be deducted right awayyou can separate some components (for example, carpets, appliances, fences, driveways) and either depreciate them faster or even deduct them right awaywhen you repair, replace or improve something (like HVAC), you have to understand extremely complex rules known as Tangible Property Regulations, so complex that even us tax professionals specializing in real estate do not always agree on specificssome rules are specific to the type of property, for example they only apply to non-residential property or only to brand new propertyand there is a whole lot more than thatSo basically, everyone can understand the general concepts, such as the difference between virus and bacteria.

Regarding refinancing and lending, local zoning laws and regulations may come into play for correct land utilization with additional units or structures.  

Most of our coastal states are increasing regulations and creating laws that favor tenants, even when the tenant is clearly violating the terms of their lease on purpose.

There are a few locations (Scottsdale) that have rolled out their own regulations over the last few years but generally it's pretty landlord-friendly in the 48th State.Feel free to DM me if you have further questions: I operate my own AirBnB unit as well as being an agent here in town.

If regulation is being relaxed in the future, this could be making sense to be invested as well.Key here is buying large lot. 

Yeah, the banks are now higher than mortgage lenders or brokers because they no longer have the throughput to handle the volume due the regulations imposed by the Dodd Frank Act (well, they cut back on their staffing because the regs made it more difficult for them to make money). 

Everything is done by official notice as outlined in your regulations.

Anyone please feel free to correct me.Could be numerous reasons as to why they've been on the market that long, could be that the owner is trying to sell them at or above market value, could be some issues with the properties, could be not much interest for properties of that type in the area, could be the area is over-saturated with housing and they're hard to get rented, any number of things.To answer your question obviously you're going to want to look inside before you even put an offer, the general rule is the landlord gives 24 hour notice to tenants.

There is no land that is free from government regulations.