With a little bit of preventative work such as no frills in the apartment (refrigerator with a water dispenser or garbage disposal), a strong lease agreement and a list of skilled tradesmen, you should be able to self-manage.

I have a good job as an air traffic controller, but I want to secure an even better future for my family by earning passive income through real estate.  

But the air, land and water pollution issues are very challenging.

Sounds like your new heater is direct vent - pulls its air from outside rather than from the conditioned space.  

No harm ever comes from doing that and it could prevent some big mistakes.

The best thing to do is to prevent problems like this during the offer/negotiation phase.

If the air is moving efficiently, the moist air will be quickly removed. ($100)Exterior door hardware should be durable and always look new.

Note that the LOC means that this project would not crimp our cash and prevent further investments.Comments from BP community welcome.

There are 4 factors of economics that are involved in every economic transaction, any business transaction, land, labor, capital and entrepreneurship (or management)3 of the 4 will always be present in any transaction, any one of the 4 may substitute for any other factor, but land will always be present (that's because you can't hover in thin air to conduct business, land is required for your airport anyway.

Any investor who tries to prevent the lender from knowing a change took place is breaking the law - so DON'T GO this route.