I've worked with contractors who initially didn't perform up to my expectations, but because they were otherwise reliable/punctual and trustworthy and charged a fair price, I kept working with them while they got in the habit of doing things the way I wanted.  

I'd say there's no harm in placing a bid.

There has to be some consideration for the materials and my time to make this habitable and even marketable in the future to a typical home buyer.Sorry to get long-winded on this.

A Property Manager has habits to keep tenants in line.

I'm not sure why the agents are so lackadaisical on those props, they still get paid good money for the "work" required.There is never any harm in walking away if you don't like the work ethic or how you've been treated.

After a few weeks, it became a habit which I still do today.

Asking to speak with them and even see the inside of the building would speak to their habits and lifestyle that much more!

If the plumbing is 'running slow' but not creating habitability issues, then you have a choice to make - listen to the tenant and make her happy for all the non-essential issues, or not!

Someone with questionable moral habits may see the opportunity and try to take advantage.  

While doing so you will have developed a habit; as well as learning and retaining real estate investing information without struggling.Bigger Pockets has various resources such as: ebooks, forums, webinars, podcasts, keyword alerts, an awards system, a learn section, colleagues, informative people in many fields of real estate, and more.