I have had decent success challenging appraisals and getting improved results.  

The resources and books you mentioned, like the BiggerPockets Ultimate Beginners Guide and The Book On Rental Property Investing, sound like excellent starting points.Prioritizing financial stability and eliminating debt is crucial, and I agree that a solid financial foundation is key to successful investing.

I’ve recommend all my clients to him in the area for the last few years and they have had great success. 

You snowball plan has a very high success rate.

I've had success turning vacant Florida land into private shooting ranges.

To maximize your chances of success, recommend sharing that and the percent increase in taxes & ins with tenant and asking them what they think a fair increase is.- If they say $0-$50, you'll have to get rid of them at end of current lease.- If they are more reasonable you may want to accept if for now, but let them know you'd be doing regular increases to get the rent more inline with market rent.Too many newbies here will tell you to get market rent or get rid of the tenant.

Has anyone ever had success doing this?

Just plan on paying the agent's fee if you are successful.

Selling PT is very difficult and as a young student it will be difficult to find much success.

These are some of the most successful people; CEO’s, tycoons, celebs, old and new money and investors on the planet.