There are some general principles for success; however, even those flip back and forth over time.  

I know some people who like to hop on a plane and see the properties and others who are fine with sight unseen.

First, we are almost universally short sighted.

The realtor wants to move some shrubs and add decorative fencing to hide the line of sight to the pot hole. so the client gets out of the car and lets it go over the cliff with everyone else in it :)  And for the record I am a degreed accountant so I'm throwing myself under the bus here also - no hate today!

Honestly, if you are worried about a repeat of your 2008 experience, I would NOT invest out of your sight, that way you keep eyes on your investment and can hand pick your tenants and spot issues right away. 

My biggest hate is that most has been funded by credit card and I’m still working excessively to pay the interest/principle each month.Maybe this is a picture of how not to do things :).  

I am thinking of offering 500 a month for the next 3-5 years (400 toward principle and 100 for intrest).

If you're calculating your monthly expenditures, include your principle payments as well. 

Also paid extra towards the mortgage principle.

I have my sights set on the market I want to invest in and I have a realtor sending me deals, but the realtors are wanting a pre-approval letter with the submission of the offer.