To spend that much I would need to gut the whole house, tear off the roof, and do everything brand new and modern.

You are probably facing an uphill battle to get it retroactively permitted at this point, and you do not want to use it as living space illegally, way too much liability.The deck may not be an issue, you generally don't need a permit for a deck that is less than 18" off the ground.....but if it is higher than that at any point, then you must tear it down to comply.

almost 100k more than mine was and the corner deli/bodega has been bought and neighbor said they will tear it down and build a condo or shops there. going in towards MLK from ocean is definitely not for the faint of heart, and even the area I got has some people cooking out on the streets/music banging loud etc, but just over the avenue 100ft away everything is quiet.coming from the heights/union city, this is the last remaining few blocks where large 2600sqft+ multifamilies are still under 350-400k totally remodeled. a mile north its all 650-700k. money must pour in just like water. literally everything surrounding greenville at this point is 100-200k more expensive.

Having two dogs myself, I know how much extra wear and tear they have had on my residence.

We would have had to buy the building next door and tear it down.

Would you say that the main way to grow is to invest new money into each property at the beginning stages of investing, or to try to stretch the original dollar as far as safely before it tears?

Depends if it’s a money grab or if there’s actual inspections involved and if they can see the work without tearing in to drywall.

If you had to pay money to get the trash removed, do extra cleaning, and other things beyond normal wear and tear you can probably keep the deposit.

You'll be adding more wear-and-tear to the property.

I have never heard of a permit needed for drywall work, unless you are tearing out all the old drywall.