Their sublease candidate submitted their credit application for approval and I approved . 

yes their site tells you in the offering details what RS fees are and also the sponsor fees if applicable.

If you need higher levels of technical training for a technical career it is different (sciences, engineering, medicine, etc.).I have a question for you: if you get a somewhat more difficult, but more applicable to RE degree (finance, law, accounting, etc.) - would that degree help you more than spending the additional time it requires on RE-specific activities?

No points, no application fee, no underwriting fee, no nothing.

If you want to keep the tenant, I'd screen them like you would any other applicant before you close; if they don't pass your standards, have the current owner end their lease before you buy.

Usually less expensive and much more real world applicable experience. 

I did an in-depth 2 part article comparing the three on numerous differences.  

My dad has 6 units in the city and does well with applicants so it's a desired place to live.

A diplomat is interested; but I am not sure about renting to such applicant due to immunity concern(you cannot evict such tenant, etc). 

The application that they completed in the beginning should give you some insight into his ability to pay, but I would still require an updated application and new credit report on just the husband as a part of drawing up a new lease.