You can also use FHA if your score is in the 625 range (not sure of the exact number but it is close).

I have a credit score of 680 with nothing negative.

You should never tie an option to a lease, or a lease to an option.If this is your residence,Offer a lease purchase (screen buyers)Separate lease, 12 mo term, market rent.Separate sale and purchase agreement, 3% earnest money, non refundable, with long term closing date, say 12 months.Send LP tenant buyer to mortgage banker IMMEDIATELY.Send LP tenant buyer to get assistance improving credit and FICO scores. 

Use neighborhood scout, walk score, etc.

A great place to understand credit scores is the Fico Forums found at MyFico.com.

I have gotten my personal finances in decent order (no debt expect a small 15 year mortgage, 785 credit score, 3 months of living expenses saved up, two pretty secure jobs in our family) I am about halfway through my real estate license education.

I'm not doing a conventional because my score is 600 not 620.

I think the best strategy is to take as many practice exams as possible until your score is above the required passing grade of 70.  

You can research this on your own and if you haven't already this might help (U of U seismograph logs) http://www.seis.utah.edu/recenteqs/.As for building right next to a fault you'll want a more professional opinion (like you requested in your OP) since there is higher risk of damage from even a lesser shock.Please note I'm not a seismologist or expert in the field but I am comfortable not purchasing earthquake insurance for my personal home currently in Spanish Fork.

Also on their site is the ability to purchase your current credit score, so you can have an idea of where you are currently at, and where you need to get to.