It has been vacant for a while and i am the only offer to strengthen my position and she just want to sell asap. what i am hung up n is should I go with another "counter offer" or a "final offer" take it or leave it? 

That way you can raise the rent whenever you want and when it’s more convenient for you and you’re in a better position to deal with a move out (if that’s what they decide to do).

He came to me because he knows I've been studying and positioning myself for the past year or so to get into REI.

Your contract is probably effectively broken since the lines of communication it has like sending notices by mail can no longer be done. 

My daughter screens her tenants & has always had a great rapport with them.Here is a notice to vacate she just received from a young couple who bought their first home.

I am in a fortunate position at my day job that allows me to listen to podcasts on the job.

You are in a great position being a pipe fitter to get into buying places that need some TLC!

Cash flow positive Lessons learned?

Any advice, feedback positive or negative is appreciated!

It's in a solid neighborhood with great schools (that's why we lived there for 17 years).THIRD, as a side note, we are also in the position to pick up another rental property within the next year or so.