Not to diminish their importance but aside from the legalities, ethics and complexities involved, if you have actually done subject to's, what are the overwhelming determining factors that would make a property a candidate for a subject to?  

Could be a motivating factor.

Regardless you have money or not, I think one of the most important factor to be a successful RE investor (or having your own business) is networking.  

You can connect Excel to external databases, write your own macros to do complex things that the Macro Generator (Recorder) can't do as well.

Currency conversion dynamics can be a huge factor in foreign investment, one I had largely overlooked.Yes, that exchange rate does takes a big bite, but that's possibly where owner financing could be beneficial.

Are there factors within my control or specific to my situation that influence this, or is it purely based on lender policy?

Don't forget to factor in state tax.You need to get with a CPA so that you can structure the deal in such a way that you demonstrate investment intent.

There are many determining factors and indicators in this market that will allow you to narrow down a solid price point that is reliable based on market activity - I do it every day for investors, investment companies, and lenders throughout the country that need Metro Atlanta home assessments. 

Does anyone think that these factors are deal breakers?

It's a cost of doing business and factor it in.