(that is, assuming you've hired an agent with experience, market knowledge, and the wisdom to be able to guide you to what you're looking for). 

.- Tenant submitted a work order for low water pressure in 2 bathrooms- Tenant submitted a work order because the garage door doesn't close all the way and left a 2-3 inch gap at the bottom- Owner initially refused to address either work order- Owner demanding the tenants place furniture pads on each piece of furniture- Owner calling multiple times to speak through the work orders, asking when they've been scheduled, calling a couple days later requesting the invoices- Owner calling because they want to access their storage in the basement so they can remove several pieces of furniture being stored- Owner now emailing requesting multiple property inspections throughout the lease cycle- Owner questioning my experience and relative PM knowledge because I'm not following up with her in a timely manner (the following day after the work order)Keep in mind, this is 2 weeks after the tenants had moved in and the tenants are very happy in the home.This is something we see on a regular basis.

I see it more a knowledge and exposure thing, reality vs perception.

Detroit can be a fantastic market with strong cash flow and good appreciation potential, but it’s definitely a unique place with its own quirks.Starting with cash is a smart move, especially in Detroit, where local knowledge and relationships can make a huge difference.

The experience/knowledge of being an agent will help you so much.  

When you are new, you can be your worst enemy (due to lack of knowledge, ego, and FOMO).If you are new, do you have a person who tells you that some deals suck?

You really have no idea how helpful all these little tidbits of knowledge are.

The amount of knowledge & information explained and provided is mind boggling honestly.

Asking to anyone who has experience, knowledge or connections in these southern texas markets, how has this or does it affect your real estate strategy and returns? 

I'm still in reconnaissance mode... so need to collect as much information and knowledge as possible before deciding what to do.  20-80 is more of a rule of thumb and not a "magical" ratio.