Refinancing, Credit Scores, and Seasoning in Columbus, Ohio

[Neddie Smith]

I am an US expat living in Austria and currently I do not have a credit score (as of 2017).

Question 1

After talking to some banks regarding refinancing my rental, I was told I will need to build a credit score to apply for a mortgage. The suggestion was to open a credit card and spend to setup a credit history. 

Do you know of any alternative "interest free" alternatives to build my credit score?

Question 2

I was told my property (in Columbus Ohio) will need to "season" for 12 months before a loan can be granted based off of the appraised value instead of the purchase price.

Is this normal and does anyone know of financial institution that will provide shorter "seasoning" periods?

Thanks for all your help!